CHAPTER XI.—LITERATURE AND HISTORY.
251. List of Publications from 1834 to1884
2. 1838. EHRENBERG, G., Polycystina (Lithocampe, Cornutella, Haliomma) in Ueber die Bildung der Kreidefelsen und des Kreidemergels durch unsichtbare Organismen. Abhandl. d. k. Akad. d. Wiss. Berlin, p. 117.
3. 1839. EHRENBERG, G., Ueber noch jetzt lebende Thierarten der Kreidebildung (Haliomma radians). Abhandl. d. k. Akad. d. Wiss. Berlin, p. 154.
4. 1844-1873 EHRENBERG, G. Vorläufige Mittheilungen über Beobachtungen von Polycystinen. Monatsber.d. k. preuss. Akad. d. Wiss. Berlin.
Republished with illustrations in the Mikrogeologie (L. N. 6) and in the two treatises of 1872 (L. N. 24) and 1875 (L. N. 25). Compare the Monatsberiehte of 1844 (pp. 57, 182, 257), of 1846 (p. 382), of 1847 (p. 40), of 1850 (p. 476), of 1854 (pp. 54, 205, 236), of 1855 (pp. 292, 305), of 1856 (pp. 197, 425), of 1857 (pp. 142, 538), of 1858 (pp. 12, 30), of 1859 (p. 569), of 1860 (pp. 765, 819), of 1861 (p. 222), of 1869 (p. 253), of 1872 (pp. 300-321), of 1873 (pp. 214-263). Only one of these small papers is of permanent value, The First Systematic Arrangement of the Polycystina in 7 families, 44 genera, and 282 species (Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, 1847, p. 54). Compare my Monograph (1862, L. N. 16), pp. 3-12, 214-219.5. 1851. HUXLEY, TH., Upon Thalassicolla, a new Zoophyte. Ann. and Mag. Nat. Hist., ser. 2, vol. viii. pp. 433-442, pl. xvi.
6. 1854. EHRENBERG, G., Mikrogeologie. Figures of numerous Polycystina on 8 plates; Taf. xviii. figs. 110, 111; Taf. xix. figs. 48-56, 60-62; Taf. xx. Nr. i., figs. 20-25, 42; Taf. xxi. figs. 51-56; Taf. xxii. figs. 20-40; Taf. xxxv. A., Nr. xix. A. fig. 5; Taf. xxxv. B. figs. 16-23: Taf. xxxvi. figs. 1-33.
7. 1855. BAILEY, J. W., Notice of Microscopic Forms of the Sea of Kamtschatka. Amer. Journ. Sci. and Arts, vol. xxii. p. 1, pl. i.
8. 1855. MÜLLER, JOHANNES, Ueber Sphaerozoum und Thalassicolla. Monaisber. d. k. preuss. Akad. d. Wiss.Berlin, p. 229.
9. 1855. MÜLLER, JOHANNES, Ueber die im Hafen von Messina beobachteten Polycystinen (Haliomma, Eucyrtidium, Dictyospyris, Podocyrtis). Monatsber. d. k. preuss. Akad. d. Wiss. Berlin,p. 671.
10. 1856. MÜLLER, JOHANNES, Ueber die Thalassicollen, Polycystinen und Acanthometren des Mittelmeeres. Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 474.
11. 1858. MÜLLER, JOHANNES, Erläuterung einiger bei St. Tropez am Mittelmeer beobachteter Polycystinen und Acanthonietren. Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 154.
12. 1858. MÜLLER, JOHANNES, Ueber die Thalassicollen, Polycystinen und Acanthometren des Mittelmeeres, Abhandl. d. k. Akad. d. Wiss. Berlin, pp. 1-62, Taf. i.-xi. (The fundamental treatise on the Radiolaria.)
13. 1858. SCHNEIDER, ANTON, Ueber zwei neue Thalassicollen von Messina.
Archiv f. Ancst. u. Physiol.,p. 38, Taf. iii. n, figs. 1-4.
14. 1858. CLAPARÈDE et LACHMANN, Echinocystida (Plagiacantha et Acanthometra). Études sur les Infusoires et les Rhizopodes, p. 458, p1. xxii. figs. 8, 9; pl. xxiii. figs. 1-6.
15. 1860. HAECKEL, ERNST, Ueber neue lebende Radiolarien des Mittelmeeres. Monateber. d. k. preuss. Akad.d. Wiss. Berlin, pp. 794, 835.
16. 1862. HAECKEL, ERNST, Die Radiolarien (Rhizopoda radiaria). Eine Monographie. 572 pp. fol. with an Atlas of 35 Copperplates.
17. 1862. BURY, Mrs., Polycystins, figures of remarkable forms in the Barbados Chalk Deposit. Ed. ii. By M. C. Cooke, 1868. 25 quarto plates, photographed from drawings by hand, containing many forms overlooked by Ehrenberg from Barbados.
18. 1863. HARTING, PAUL, Bijdrage tot de Kennis der mikroskopische Fauna en Flora van de Banda-Zee (Diep-Zee-Polycystinen). Verhandl. d. Kon. Akad van. Wetenseh. Amsterdam, vol. ix. p. 30, pis. i.-iu.
19. 1865. HAECKEL, ERNST, Ueber den Sarcode-Körper der Rhizopoden (Actinelius, Acanthodesmia, Cyrtidosphaera, &c.). Zeitschr. f. wiss. Zool., Bd. xv. p. 342, Taf. xxvi.
20. 1867. SCHNEIDER, ANTON, Zur Kenntniss des Baues der Radiolarien (Thalassicolla). Archiv f. Anat.u. Physiol., 1867, p. 509.
21. 1870. HAECKEL, ERNST, Beiträge zur Plastiden Theorie (Myxobrachia; Amylum in den gelben Zellen). Jenaische Zeitschr. für Naturw., Bd. v. p. 519-540, Taf. xviii.
22. 1871. CIENKOWSKI, L., Ueber Schwärmer-Bildung bei Radiolarien. Archiv f. mikrosk. Anat., Bd. vii. p. 372-381, Taf. xxix.
23. 1872. WAGNER, N., Myxobrachia Cienkowskii. Bull. d. Acad. St. Petersburg, vol. xvii. p. 140.
24. 1872. EHRENBERG, GOTTFRIED, Mikrogeologische Studien über das kleinste Leben der Meeres-Tiefgründe aller Zonen und dessen geologischen Einflusa. Abhandl. d. k. Akad. d. Wiss. Berlin, 1872. Mit 12 Tafeln. (The Latin diagnoses of 113 new species here mentioned are given in the Monatsberichte of April 25, 1872, pp. 300-321.)
25. 1875. EHRENBERG, GOTTFRIED, Polycystinen-Mergel von Barbados (Fortsetzung der Mikrogeologischen Studien). Abhandl. d. k. Akad. d. Wiss. Berlin,1875, 168 pag. mit 30 Tafeln. (The Latin diagnoses of 265 species here recorded are given in Namensverzeichniss der fossilen Polycystinen von Barbados. Monatsber. d. k. preuss. Akad. Wiss. Berlin, Jan. 30, 1873, pp. 213-263.)
26. 1876. HERTWIG, RICHARD, Zur Histologie der Radiolarien. Untersuchungen über den Bau und die Entwickelung der Sphaerozoiden und Thalassicolliden. 91 pp. with 5 plates.
27. 1876. MURRAY, JOHN, Challengerida. Preliminary Reports on Work done on board the Challenger. Proc. Roy. Soc. Lond., vol. xxiv. pp. 471-536, p1 xxiv.
28. 1876. ZITTEL, KARL, Palaeozoologie, Bd. i. pp. 114-126, figs. 46-56.
29. 1876. ZITTEL, KARL, Ueber fossile Radiolarien der oberen Kreide. Zeitschr. d. deutsch. geol.Gesellsch, Bd. xxviii. pp. 75-96, Taf. ii. (with figures of six Cretaceous species).
30. 1877. MIVART, ST. GEORGE, Notes touching recent researches on the Radiolaria. Journ. Linn. Soc. Lond. (Zool), vol. xiv. pp. 136-186. (Historical sketch of previous literature.)
31. 1877. WYVILLE THOMSON, The Voyage of the Challenger-The Atlantic, vol. i. pp. 231-237, figs. 51 -54; vol. ii. pp. 340-343, figs. 58, 59, &c.
32. 1878. HAECKEL, ERNST, Das Protistenreich, eine populäre Uebersicht über das Formengebiet der niedersten Lebewesen, pp. 101-104.
33. 1879. HERTWIG, RICHARD, Der Organismus der Radiolarien. Jenaische Denkscliriften, Bd. ii. Taf. vi.- xvi pp. 129-277.
34. 1879. HAECKEL, ERNST, Ueber die Phaeodarien, eine neue Gruppe kieselschaliger mariner Rhizopoden. Sitzungsb. med. -nat. Gesellsch. Jena, December 12, 1879.
35. 1880. STÖHR, EMIL, Die Radiolarien-Fauna der Tripoli von Grotte (Provinz Girgenti in Sicilien). Palaeontographica, Bd. xxvi. pp. 71-124, Taf. xvii.-xxiii. A preliminary communication regarding this fauna from the tripoli is given in Tagebl. d. Naturf. Versam.ml. München, 1877.
36. 1880. PANTANELLI, DANTE, I Diaspri della Toscana e i loro fossii. Real. Accad. del Lincei, ser. 3, vol vii. pp. 13-34, Tab. i. Radiolaria di Calabria. Atti. Soc. Tosc.,p. 59.
37. 1881. HAECKEL, ERNST, Prodromus Systematis Radiolarium, Entwurf eines Radiolarien-Systems auf Grund von Studien der Challenger-Radiolarien. Jenaische Zeitschr.für Naturw., Bd. xv. pp. 418-472.
38. 1881. BRANDT, KARL, Untersuchungen an Radiolarien. Monatsber. d. k. preuss. Akad.d. Wiss. Berlin, (April 21), pp. 388-404, Taf. i.
39. 1882. BRANDT, KARL, Ueber die morphologische und physiologische Bedeutung des Chlorophylls bei Thieren. I. Artikel. Archiv f. Anat. u. Physiol., pp. 125-151, Taf. i. II. Artikel. Mittheil. a. d. Zool. Station zu Neapel, Bd. iv. pp. 193-302, Taf. xix., xx.
40. 1882. BÜTSCHLI, OTTO, Beiträge zur Kenntniss der Radiolarien-Skelette, insbesondere der der Cyrtida. Zeitschr. f. wiss. Zool., Bd. xxxvi. pp. 485-540, Taf. xxxi.-xxxiii.
41. 1882. BÜTSCHLI, OTTO, Radiolaria. In Bronn's Klassen und Ordnungen des Thierreichs. Bd. i., Protozoa, pp. 332-478, Taf. xvn.-xxxii.
42. 1882. GEDDES, PATRICK, Further Researches on Animals containing Chlorophyll. Nature, pp. 303-305.
43. 1882. GEDDES, PATRICK, On the Nature and Functions of the "Yellow Cells" of Radiolarians and Coelenterates. Proc. Roy. Soc. Edin., p. 377.
44. 1882. DUNIKOWSKI, EMIL, Die Spongien, Radiolarien mid Foraminiferen der Unter-Liassischen Schichten vom Schafberg bei Salzburg. Denkschr. d. k. Akad. d. Wiss. Wien, Bd. xlv. pp. 22-34. Taf. iv.-vi.
45. 1882. PANTANELLI, DANTE, Fauna miocenica di Radiolari del Appennino settentrional. Boll. Soc. Ceo?. Ital.
46. 1883. HAECKEL, ERNST, Die Ordnungen der Radiolarien (Acantharia, Spuinellaria, Nassellaria, Phaeodaria). Sitzungsb. med.-nat. Gesellsch. Jena, February 16, 1883.
47. 1883. HERTWIG, OSCAR, Die Symbiose oder das Genossenschaftsleben im Thierreich. 56. Versamml. Deutscher Naturf. u. Aerzte, Freiburg i/B.
48. 1883. RÜST, WILHELM, Ueber das Vorkommen von Radiolarien-Resten in kryptokrystallinischen Quarzen aus dem Jura und in Koprolithen aus dem Lias. 56. Versamml. Deutscher Naturf. u. Aerzte, Freiburg i/B.
49. 1884. CAR, LAZAR, Acanthometra hemicompressa (= Zygacantha semicompressa). Zool. Anzeiger, p. 94.
50. 1884. HAECKEL, ERNST, Ueber die Geometrie der Radiolarien (Promorphologie).
med.-nat. Gesellsch. Jena, November 22, 1883.
251 A. Supplementary List of Works Published in 1885 :-
51. 1885. D. RÜST, Beiträge zur Kenntniss der fossilen Radiolarien aus Gesteinen des Jura. 45 pp. 4to, and 20 plates. Palaeontographica, Bd. xxxi. (oder iii. Folge, vii. Band).
52. 1885. KARL BRANDT, Die koloniebildenden Radiolarien (Sphaerozoeen) des Golfes von Neapel und der angrenzenden Meeres-Abschnitte. 276 pp. 4to, and 8 plates.
53. 1885. JOHN MURRAY, Narrative of the Cruise of H.M.S. Challenger, with a general account of the scientific results of the Expedition. Vol. i. First part, pp. 219-227, pl. A. Second part, pp. 915-926, p1. N. fig. 2.
54. 1885. ERNST HAECKEL, System der Acantharien. Sitzungsb. med.-nat. Gesellsch. Jena., November 13.
Since the printing of this Report began in 1884 and was far advanced
in 1885, it was impossible to include the important works of Rüst
and Brandt (L. N. 51, 52) in the descriptive portion, so that they are
only referred to in the Introduction.
251 B. Phaulographic Appendix :-A list of absolutely worthless literature, which contains either only long known facts or false statements,and may hence be entirely neglected with advantage. Compare § 252, and also L. N. 26, p. 9.
55. 1865. WALLICH, G. C., On the structure and affinities of Polycystina. Trans. Micr. Soc. Lond., voL xiii. pp. 57-84. (Compare L. N. 26, p. 9.)
56. 1879. WALLICH, G. C., Observations on the Thalassicollidae. Ann. and Mag. Nat. Hist., ser. 4, vol. iii. p. 97.
57. 1866. STUART, ALEXANDER, Ueber Coscinosphaera ciliosa, eine neue Radiolarie (= Globigerina echinoides !!). Zeitschr. f. wiss. Zool., Bd. xvi. p. 328, Taf. xviii. (Compare L. N. 26, p. 9.)
58. 1870. STUART, ALEXANDER, Neapolitanische Studien. Göttinger Nachr., p. 99, and Zeitschr. f. wiss. Zool. Bd. xxii. p. 290 ("Blue Siliceous Crystals" in Collozoum inerme !).
59. 1871. MACDONALD, JOHN DENIS, Remarks on the Structure of Polycystina (Astromma Yelvertoni=Euchitonia Mülleri). Ann. and Mag. Nat. Hist., ser. 4, vol. viii. p. 226.
60. 1871. DOENITZ, W., Beobachtungen iiber Radiolarien. Archiv f. Anat. u. Physiol., 1871, p. 71, Taf. ii. (Compare L. N. 26, p. 7.)
252. Progress of our Knowledge of the Radiolaria from 1862 to 1885.-The history of our scientific knowledge of the Radiolaria extends over about half a century (from 1834 to 1885). A historical and critical discussion of the works which appeared within the first twenty-eight years of this period (from 1834 to 1862) is contained in the historical introduction to my Monograph (L. N. 16, pp. 1-24); I shall therefore give here only a brief survey of the investigations published during the last twenty-three years (from 1862 to 1885). The most important steps in our progress during this period we owe to the following naturalists :-Cienkowski (1871), Ehrenberg (1872 and 1875), Richard Hertwig (1876 and 1879), Karlt Brandt (1881 and 1885), Bütschli (1882), and Rüst (1885). To the valuable works of these authors must be added a number of smaller contributions, which are recorded in the foregoing Bibliography. Some communications from dilettanti, written with insufficient knowledge of the subject, and hence of no value, are mentioned for the sake of completeness in the "Phaulographic Appendix" (compare L. N. 55-60, also L. N. 26, p. 9).
The first important advance in our knowledge of the organisation of the Radiolaria, made after the publication of my Monograph (1862), was the demonstration of the nature of the extracapsular "yellow cells." In the year 1870 I showed that these yellow cells contain starch (L. N. 21, p. 519). I regarded them, as did all authors up to that time, as integral parts of the Radiolarian organism, and hence considered this to be multicellular; for no doubt was possible regarding the true cellular nature of these remarkable, nucleated, yellow gbobules, which I had thoroughly studied in 1862. It was first shown by Cienkowski in 1871 that the yellow cells of the Collodaria remain unchanged even after the death of these organisms, "that they continue to grow uninterruptedly, and eventually multiply by division" (L. N. 22, pp. 378-380, Taf. xix. figs. 30-36). Cienkowski concluded from these important observations that the yellow cells are not integral parts of the Radiolarian body, but "parasitic structures," independent, unicellular organisms, which live only as parasites in the body of the Radiolaria (compare § 90).
This important recognition underwent ten years later a further development
and complete establishment by the extensive investigations of Karl Brandt
(L. N. 38, 39)
and Patrick Geddes (L. N. 42, 43). This arrangement was compared by Brandt to the remarkable symbiosis of the Algoid gonidia and Fungoid hyphae in the organisation of the Lichens, which had been recently discovered, and since he recognised the independent nature of the yellow cells, as unicellular Algae, in all divisions of the Radiolaria, he founded for them the genus Zooxanthella. Geddes named them Philozoon, and showed experimentally that they give out oxygen under the influence of sunlight (compare § 90). The great physiological importance of the yellow cells in the metastasis of the Radiolaria, and, when they are developed in large quantities, in the economy of marine organisms in general, has recently been insisted upon by Brandt (see § 205 and L. N. 52, pp. 65-71, 86-94).
The proof that the yellow cells do not belong to the Radiolarian organism itself, but only live parasitically in it, was a necessary preliminary to the very important step which next took place in our knowledge of the organisation of the Radiolaria. This step consisted in the demonstration that the whole body of the Radiolaria, like that of all other Protista, is only a single cell. It was Richard Hertwig who in two remarkable works (L. N. 26, 33) firmly established this fundamental theorem of the unicellular nature of the Radiolaria. In his treatise on the histology of the Radiolaria (L. N. 26, 1 876) he published complete investigations into the structure and development of the Sphaerozoida and Thalassicollida. Since he made use of the modern methods of histological examination, and especially of staining fluids, which he was the first to apply to the study of the Radiolaria, he was able to show that no true cells (apart from the parasitic yellow cells) are to be found in their bodies, but rather that all their morphological components are to be regarded as differentiated parts of a single true cell, and in particular that the central capsule includes a genuine nucleus.
A wider foundation for this important discovery and its applicability to all divisions of this extensive class, was given by Hertwig in a second work on the organisation of the Radiolaria (L. N. 33, 1879). Among the numerous discoveries by which this work enriched the natural history of the Radiolaria must be specially mentioned the recognition of the fundamental differences exhibited by the main divisions of the class in the structure of their central capsule. Hertwig first observed that the capsular membrane is double in the PHAEODARIA but single in the other Radiolaria (§ 56); the former he named "TRI-PYLEA" because he discovered in their capsular membrane a large, peculiarly constructed main opening and two small accessory openings. The NASSELLARIA, in which he found a single porous area at the basal pole of the main axis, with a cone of pseudopodia rising from it, he called on this account "MONOPYLEA"; whilst the other Radiolaria, whose capsular membrane is perforated on all sides with fine pores, were termed "PERIPYLEA." Besides the central capsule, Hertwig laid stress upon the significance of the gelatinous envelope as a constant and important constituent of the body. He also devoted attentive consideration to the morphology of the skeleton, and on the basis of certain phylogenetic conclusions which he drew from it, he arrived at an improved systematic arrangement in which he distinguished six orders :-( 1) Thalassicollea, (2) Sphaerozoea, (3) Peripylea, (4) Acanthometrea, (5) Monopylea, (6) Tripylea. The numerous isolated discoveries with which Hertwig enriched the morphology of the Radiolaria, have been already alluded to in the appropriate paragraphs in the anatomical portion of this Introduction (see L. N. 42, pp. 340, 341).
The new and interesting group, which was thus erected into an order
under the name TRIPYLEA, I had already a year previously separated from
the other Radiolaria as "Pansolenia" in my Protistenreich (L. N.
32, p. 102). Since, however, neither the three capsular openings of the
TRIPYLEA nor the skeletal tubes of the Pansolenia are present in all the
families of this extensive order, I substituted in 1879 the more suitable
name PHAEODARIA, which is applicable to all members of the group (L. N.
34). In the preliminary memoir then published regarding the Phaeodaria,
a New Group of Siliceous Marine Rhizopods, I distinguished four orders,
and thirty-eight genera. The great majority of these new forms (among which were no less than 465 different species) were first discovered by the deep-sea investigations of the Challenger. John Murray was the first who called attention to the great abundance in the deep sea of these remarkable Rhizopods, and to the constant presence of their peculiar, dark, extracapsular pigment body (phaeodium); even in 1876 he described a portion of them as Challengerida (L. N. 27, p. 536; L. N. 53, p. 226). The earliest observations on the PHAEODARIA were made at Messina in 1859, where I examined five genera of this remarkable group alive (compare p. 1522 and L. N. 16).
By the discovery that the PHAEODARIA, although differing in important respects from the other Radiolaria, still conform to the definition of the class, a new and extensive series of forms was added to this latter, and by their closer investigation a fresh source of interesting morphological problems was disclosed. In other groups, however, morphology was advanced by comparative anatomical studies. In addition to the smaller contributions of various authors, mentioned in the foregoing bibliography, I may specially refer to the valuable Beiträge zur Kenntniss der Radiolarien -Skelete, insbesondere der der Cyrtida by O. Bütschli (L. N. 40, 1882). On the basis of careful comparative anatomical studies, investigations into the skeletal structure of a number of fossil Cyrtoidea and critical application of the recently published researches of Ehrenberg into the Polycystina of Barbados (L. N. 25), Bütschli attempted to derive the complicated relations of the Monopylean skeletons phylogenetically from a simple primitive form,-the primary sagittal ring. Even if this attempt did not actually solve the very difficult morphological problem in question, still the critical and synthetic mode in which it was carried out deserves full recognition, and furnishes the proof that the comparative anatomy of the skeleton in the Radiolaria not less than in the Vertebrata, is a most interesting and fruitful field of phylogenetic investigation. A further demonstration. of this was furnished by Bütschli in the general account of the organisation of the Radiolaria which he published in 1882 in Bronn's Klassen und Ordnungen des Thierreichs (L. N. 41).
In our knowledge of the developmental history of these Prootista the last two decades have witnessed less progress than in their comparative anatomy. The most important advance in this direction has been the proof that in all the main groups of the class the contents of the central capsule are used in the formation of swarm-spores. The movements of these zoospores in the central capsule had indeed been observed by several previous authors in the case of the SPUMELLARIA and ACANTHARIA (L. N. 10, 13, 16; compare also § 142, Note A). The origin of the flagellate spores from the contents of the central capsule and their peculiar constitution were, however, first described fully by Cienkowski in 1871 (L. N. 22, p. 372). Soon after this, R. Hertwig discovered that in the social Radiolaria (Polycyttaria or Sphaerozoea) two different forms of zoospores are formed, one with, the other without crystals, and that the latter are also divided into macrospores and microspores (compare L. N. 26, and § 142). Recently this sexual differentiation has been shown by Karl Brandt to exist in all the groups of Sphaerozoea, and its regular interchange with the formation of crystal-spores has been interpreted as a true "alternation of generations's (compare L. N. 52 and also § 216). The other forms of development also, especially reproduction by cell-division (§ 213) and gemmation (§ 214), have been elucidated by the recent investigations of the same author.
The palaeontology of the Radiolaria has of late made important and interesting advances. Until ten years ago fossil remains of this class were known exclusively from the Tertiary period; almost the only source of our information was to be found in the researches of Ehrenberg, commenced in 1838, continued in his Mikrogeologie in 1854, and concluded in his last work (L. N. 25) published in 1875 (compare L. N. 16, pp. 3-9, 191-193). In the year 1876 a number of Mesozoic Radiolaria from the chalk were described by Zittel (L. N. 28), and afterwards others from the Jura by Dunikowski (L. N. 44). That fossil Radiolaria occur in Mesozoic formations, especially in the Jura, as well preserved and, as abundantly as in the Tertiary rocks of Barbados, was shown in 1883 by Rüst (L. N. 48). By the examination of numerous thin sections he discovered that in all the main divisions of the Jurassic formation (Lias, Dogger, Malm) there are distributed jaspers, flints, cherts, and other quartzites, which consist largely of the siliceous shells of Polycystina; the same is true also of many Coprolites found in the Jura. The full account of these and the descriptions and figures of 234 Jurassic species, distributed in 76 genera, are contained in the Beiträge zur Kentniss der fossilen Radiolarien aus Gesteinen des Jura (L. N. 51, 1885). But even in the older rocks, the Trias, the Permian, and Carboniferous systems, and even as far downwards as the Silurian and Cambrian formations, Rüst has recently shown the existence of fossil Radiolaria, and thus increased the known period of the developmental history of the class by many millions of years (§ 244).
The great significance of the Radiolaria in geology and palaeontobogy has been brought into new light not only by these extensive discoveries, but also by the important relations which have been shown to exist between the Radiolarian rocks and the deep-sea deposits of the present day. In this direction the wonderful discoveries of the Challenger, and especially the investigations of the deep-sea deposits by Wyville Thomson (L. N. 31) and John Murray (L. N. 27), have furnished us with new and valuable information (compare §§ 236-239, and §§ 245-250). The Tertiary Polycystine formations of Barbados and the Nicobar Islands, with which we have been acquainted for the last forty years, as also the Mesozoic Radiolarian quartzes, which have only recently been made known to us from the Jura, are ascertained to be fossil representatives of the same deep-sea deposits which now occur in the form of Radiolarian ooze (§ 237), and to some extent also of Globigerina ooze and red clay (§- 238, 239), on the bottom of the ocean, at depths of from 2000 to 4500 fathoms.
These investigations into fossil Radiolaria and their comparison with recent deep-sea forms have a further general significance, inasmuch as the identity of many living and fossil species from the Tertiary formation has been shown beyond all doubt. In this direction the numerous measurements and accurate comparisons which I have made during the last ten years of the abyssal forms in the Challenger collection, and of fossil species from Barbados and Caltanisetta, have brought to light many important facts. In this I had the able assistance of my friend, Dr. Reinhold Teuscher (compare § 250, and p. 1760). Further valuable contributions in this direction are found in the careful observations and comparative measurements recently published by Emil Stöhr (L. N. 35, 1880), regarding the Radiolarian fauna of the Tripoli of Grotte in the province of Girgenti, Sicily. From these it appears that the number of Miocene species which are still extant, is much greater than would appear from the results of Ehrenberg.
Ehrenberg himself, towards the end of his long and laborious life, collected the results of the systematic and palaeontological researches, which he had begun thirty- seven years previously (L. N. 16, pp. 3-12) into the Polycystina, in two large works (L. N. 24, 25). The first treatise (L. N. 24, 1872) contains the Mikrogeobogische Studien über das Kleinste Leben der Meeres-Tiefgründe aller Zonen und dessen geologischen Einfluss, with a list of 279 Polycystina observed by him from the deep-sea, as well as figures of 127 species. The second work (L. N. 25, 1875) contains the Fortsetzung der Mikrogeologischen Studien, mit specieller Rücksicht auf den Polycystinen-Mergel von Barbados; the list of fossil Polycystina observed by him includes 325 species, of which 26 are still extant; 282 of them are figured on the thirty plates accompanying the memoir. By means of these numerous figures, as well as by the appended systematic and chorobogical tables, Ehrenberg furnished a welcome supplement to the numerous communications regarding the Polycystina, which he had made to the Berlin Academy since 1838, and which he had published in his Mikrogeobogie in 1854. It will always be the merit of this zealous and indefatigable microscopist that he first called attention to the great wealth of forms existing in this class; he separated systematically about 500 species, and published drawings of about 400; in addition to which he was the first to lay stress upon the great chorological and geological importance of the Radiolaria.
With these systematic and descriptive, chorobogical and palaeontological works, however, which relate exclusively to the Polycystina, the merits of the famous naturalist of Berlin are exhausted as regards this class of animals. Of the organisation of the Radiolaria, Gottfried Ehrenberg remained entirely ignorant up till his death in 1876. All that a number of famous naturalists had observed during a quarter of a century as to the structure and life-history of the Radiobaria, all the important discoveries of Huxley (1851), Johannes Müller (1858), Claparède (1858), Cienkowski (1871), and many others (L. N. 1-22), and all that I had published in my Monograph (1862) on the basis of three years' study of their anatomy and physiology-all this Ehrenberg ignored, or rather, he regarded it all as worthless rubbish of science, as a chaos of devious errors, resting upon incomplete observations and false conclusions. His strange "special considerations regarding the Polycystina" (L. N. 24, pp. 339-346) and the general "concluding remarks" (L. N. 25, pp. 146-147) leave no room for doubt on this point. Ehrenberg indeed doubted to the last whether any observer had seen living Radiolaria at all (L. N. 25, p. 108).
The invincible obstinacy with which Ehrenberg maintained his preconceived opinion of the high organisation of the Radiolaria, and entirely ignored the contrary observations of other naturalists, is explained by the consistency with which he held to the end the "principle peculiar to himself of the universally equal development of the animal kingdom" (L. N. 16, p. 7). From the complicated arrangement of their siliceous shells he concluded that the animals inhabiting them must possess a structure correspondingly complex, and nearly related to that of the Echinodermata (Holothuria). Like all other animals the Radiolaria must possess systems of organs for locomotion, sensation, nutrition, circulation, and reproduction. Whilst Ehrenberg originally interpreted the Polycystina as siliceous Infusoria polygastrica, and regarded them as compound Arcellina, he afterwards classed them sometimes with the Echinodermata (Holothuria), sometimes with the Bryozoa, sometimes with the Oscillaria (see L. N. 41, p. 336). Although a decided opponent of the cell-theory he called them " multicellular animal cubes" (Polycystina), interpreting the pores of the siliceous shell as cells. Today the opposite term (Monocystina) might be adopted to express their unicellular organisation. It was a remarkable irony of fate that in the self-same year (1838) in which Schwann of Berlin made by his foundation of the cell theory the greatest advance in the whole of Biological Science, that Ehrenberg, all his life the most zealous opponent of that theory, published his great work on the Infusoria, and at the same time established the "family of multicellular animalcules or Polycystina" (Ia. N. 16, p. 4).
The "short systematic survey of the genera of cellular animalcules" given by Ehrenberg in 1875 (L. N. 25, p. 157), is only a new edition, increased by sixteen genera, of his first systematic arrangement of the Polycystina of 1847 (L. N. 4, p. 53). Since I have already given a full discussion of this in my Monograph (L. N. 16, pp. 214-219), I need only here remark that a correct understanding of his very inadequate generic diagnoses is only possible by the aid of his figures. Relying upon these I have retained almost all Ehrenberg's genera, although entirely new definitions of most of them have been necessary.
The same is true also of the two orders which Ehrenberg distinguished in his class of "Zellenthierchen." The first order is constituted by his "Netzkörbchen" (Monodictya or NASSELLARIA) formerly known as "Polycystina solitaria"; they include our Cyrtoidea, the greater part of Hertwig's Monopylea. Ehrenberg's second order is the "Schaumsternchen" (Polydictya or SPUMELLARIA), previously called "Polycystina composita"; they include the Peripylea of Hertwig, as well as the Spyridina (our Spyroidea), which belong properly to the NASSELLARIA. Although Ehrenberg's statements regarding the organisation of both these orders were quite erroneous, and his knowledge even of the structure of their shells very defective, I still thought it advisable to retain his names for the groups, since they constituted his one successful effort in the systematic treatment of the Radiolaria (compare L. N. 41, p. 336).
The sketch of a systematic arrangement of the Radiolaria (L. N. 37), which I published in 1881 on the basis of the study of the Challenger Radiolaria, resembles, in respect of seven orders being distinguished, the new system which R. Hertwig founded in 1879, in consequence of the variations which he discovered in the structural relations of the central capsule (L. N. 33, p. 133). It differs, however, inasmuch as his Sphaerozoea (my Polycyttaria) are here divided into two orders, Symbelaria (Collophaerida) and Syncollaria (Sphaerozoida). In that sketch too I separated for the first time the two subclasses Holotrypasta (Porulosa) and Merotrypasta (Osculosa). The fifteen families established by Hertwig were then raised to twenty-four. The six hundred and thirty genera, which I then distinguished, are still for the most part retained, some, however, in a restricted sense, or with amended definitions.
The differential characters of the orders and families of the Radiolaria, given in the Prodromus in 1881, were amended in a further communication which I gave in 1883 regarding the orders of the Radiolaria (L. N. 46, p. 17). There I reduced the seven orders to four, the structural relations of the central capsule being precisely the same in the Pobycyttaria and Collodaria as in the Peripylea. The survey of the affinities of the class was thus rendered much simpler and clearer, and the hypothetical genealogical tree, which I then published, has been still further carried out in Chapter VI. of the present Introduction (see §§ 153-200).
253. General Survey of the Growth of our Systematic Acquaintance with the Radiolaria from 1834 to 1885.
1834. MEYEN (L. N. 1) describes 2 genera and species of Collodaria:-Sphaerozoum fuscum and Physematium atlanticum.
1838. EHRENBERG (L. N. 2) founds the family Polycystina upon 3 fossil genera (with 6 species) :- Lithocampe, Cornuteila, Haliomma..
1847. EHRENBERG (L. N. 4) publishes his preliminary communications regarding the fossil Polycystina of Barbados and distinguishes 282 species, distributed in 44 genera and 7 families. In the tabular view of the genera he distinguishes two orders :-I. Solitaria—(1) Halicalyptrina, (2) Lithochytrina, (3) Eucyrtidina; and II. Composita:—(4) Spyridina, (5) Calodictya, (6) Haliommatina, (7) Lithocydidina (compare L. N. 16 pp. 214-219).
1851. HUXLEY (L. N. 5) gives the first accurate account of living Radiolaria, and describes 2 species of the genus Thalassicolla (nucleata and punctata); under the latter are included 4 genera of Sphaerozoea:- Collozoum, Sphaerozoum,Collosphaera, Siphonosphaera (compare L. N. 16, pp. 12-14).
1854. EHRENBERG (L. N. 6) publishes in his Mikrogeologie, figures of seventy-two species of fossil Polycystina (without descriptions).
1855. JOHANNES MÜLLER (L. N. 8, p. 248) describes the first Acanthometra, and elucidates its affinity to Huxley's Thalassicolla and Ehrenberg's Polycystina.
1858. JOHANNES MÜLLER (L. N. 12) establishes the new group Radiolaria as a special order of the Rhizopoda, and includes in it the Thalassicolla, Polycystina, and Acanthometra as closely related families. He opposes these radiate Rhizopoda to the Polythalamia, and describes 50 species observed by him living in the Mediterranean, these he arranges in 20 genera, of which 10 are new. The figures are contained in eleven plates (see L. N. 16, pp. 22-24).
1858. CLAPARÈDE (L. N. 14) describes the first Plectoidean (Plagiacantha arachnoides) and two species of Acanthomnetra, which he had observed living in Norway (see L. N. 16, p. 18).
1860. EHRENBERG (L. N. 4) gives a short diagnosis of 22 new genera of Polycystina, based on the investigation of numerous deep-sea species brought up by Brooke from the depths of the Pacific Ocean. The number of his genera is thus increased to 66 (compare L. N. 16, pp. 10, 11).
1862. ERNST HAECKEL (L. N. 16) embraces in his Monograph of the Radiolaria all the species hitherto known either by figures or descriptions, and arranges them in 15 families and 113 genera; of which latter 46 are new. The number of new species observed living amounts to 144. In a "survey of the Radiolarian fauna of Messina" (p. 565) he records 72 genera and 169 species. Most of these are figured in the accompanying atlas of thirty-five plates.
1862. BÜRY (L. N. 17) gives in an atlas of twenty-five plates, photographed from drawings, the figures of numerous fossil Polycystina of Barbados (without descriptions), of which many are new species overlooked by Ehrenberg (compare § 242, above).
1872. EHRENBERG (L. N. 24) gives a list of names (without description) of all the Polycystina observed by him from the bottom of the sea, 279 species, of which 127 are figured on twelve plates.
1875. EHRENBERG (L. N. 25) gives a list of names of all the fossil Polycystina observed by him (from Barbados, the Nicobar Islands and Sicily), 326 species, of which 282 are figured (compare § 242 above). In a new "Systematic Survey of the Genera" the number of these is given as 63. The 7 families are the same as given in 1847 (see above), as also the two orders (NASSELLARIA = Solitaria, SPUMELLARIA = Composita).
1876. ZITTEL (L. N. 29) describes the first fossil Radiolaria from the chalk (6 species) and establishes the new Cyrtoid genus Dictyomitra.
1876. JOHN MURRAY (L. N. 27) establishes the new family Challengerida, and figures 6 new generic types of PHAEODARIA.
1879. RICHARD HERTWIG (L. N. 33) first describes the fundamental differences in the structure of the central capsule, and in accordance with them divides the Radiolaria into six orders (1) Thalassicollea, (2) Sphaerozoea, (3) Peripylea, (4) Acanthometrea, (5) Monopylea, (6) Tripylea (p. 133). These are subdivided into 18 families, and their phylogenetic affinities discussed (p. 137). On the ten plates, several new species from Messina are figured, among them the types of several new genera (Cystidium, Coelacantha, .Echinosphaera)(compare § 252).
1879. ERNST HAECKEL (L. N. 34) founds the order PHAEODARIA as a "new group of marine siliceous Rhizopods," and distinguishes in it 4 suborders, 10 families and 38 genera.
1880. EMIL STÖHR (L.N. 35) describes the Miocene "Radiolarian fauna of the tripoli from Grotte in Sicily," 118 species, of which 78 are new; among them is the new genus Ommatodiscus, the type of a new family, Ommatodiscida. The new species are figured on seven plates.
1880. DANTE PANTANELLI (L. N. 36) describes 30 species of fossil Polycystina from the jaspers of Tuscany, which he regarded as Eocene, but which were probably of Jurassic origin (compare § 243, note B, above).
1881. ERNST HAECKEL (L. N. 37) publishes a "Sketch of a classification of the Radiolaria on the basis of the study of the Challenger Collection," and distinguishes in his "conspectus ordinum" (p. 421) 2 subclasses and 7 orders, and in the "prodromus systematis Radiolarium" (pp. 423-472) 24 families with 630 genera, among which are more than 2000 new species.
1882. BÜTSCHLI (L. N. 40) on the basis of studies of the fossil Monopylea of Barbados, investigates the "mutual relations of the Acanthodesmida, Zygocyrtida and Cyrtida," and gives a critical revision of the genera of these "Cricoidea;" a number of new species are described and figured (Tafs. xxxii., xxxiii), and some new genera of Stichocyrtida established (Lithostrobus, Lithomitra, &c.).
1882. DUNIKOWSKI (L. N. 44) describes 18 new fossil Polycystina from the lower lias of the Salzburg Alps, among them the types of 3 new genera (Ellipsoxiphus, Triactinosphaera,and Spongocyrtis).
1883. ERNST HAECKEL (L. N. 46) revises the 4 orders and 32 families of Radiolaria, and gives more accurate definitions of them, as well as of the 2 subclasses (I. Holotrypasta = ACANTHARIA and SPUMELLARIA; II. Merotrypasta = NASSELLARIA and PHAEODARIA).
1885. D. RÜST (L. N. 51) describes 234 new species of fossil Radiolaria from the Jura, and illustrates them by twenty plates. Among theni are 103 SPUMELLARIA, 130 NASSELLARIA, and 1 PHAEODARIA; these are contained in 35 genera, of which 20 belong to the Porulosa, and 15 to the Osculosa.
254. Statistical Synopsis of the Twenty Orders :-
Note. -In the tenth and eleventh columns the relative abundance of each order at or near the surface and near the bottom is approximately indicated by the letters A-E, which have the following significance :-A, abundant; B, very numerous; C, many (medium quantity); D, few; E, very few.