NATURE 



[May 5, 1898 



which unfolded and grew after entering the egg. This 

 view never obtained universal acceptance, and it was 

 abandoned by every one at the close of the eighteenth 

 century, as Wolffs view of development became fashion- 

 able ; but the belief which then grew up was further from 

 the truth than that previously held, for it was maintained 

 that spermatozoa were parasites of extraneous origin, 

 which played no part whatever in the process of fertilis- 

 ation. This belief was finally destroyed by the researches 

 of Kolliker, who showed conclusively that spermatozoa 

 arise from the tissues of the male gonad, and said in 

 1847 : " Ich betrachte sie als befruchtende Princip und 

 glaube, dass sie durch Beriihrung der Eier in denselben 

 ein neues Leben erwecken" — thus leading the way directly 

 to modern views. These papers again, besides establish- 

 ing an important general proposition, contain statements 

 of value on many points of detail, among which the 

 descriptions of the large non-motile male elements of 

 the higher Crustacea may be nientioned. 



The two series of memoirs referred to contain perhaps 

 the most fundamental results achieved before going to 

 Wurzburg in 1847 ; but they give no idea of the amount 

 of work actually done before that date. In the field of 

 pure histology must be mentioned the memoir on the 

 Pacinian bodies, written in cojunction with Henle (1844); 

 the important demonstration of the whole course of the 

 connection between a medullated nerve fibre and a nerve 

 cell (1845) ; a memoir on the spleen, and another on the 

 synovial membranes (1847); also a preliminary account 

 of the researches on the structure of smooth muscle, 

 which were fully described later. Of more purely 

 zoological interest are the papers on the hectocotylus of 

 Cephalopods, in which the trematode hypothesis is shown 

 to be untenable ; the paper on the marginal bodies of 

 Medusae (1843), which contains the earliest recognition 

 of the nature of the otocysts in these animals ; the 

 description of the remarkable Rhodope Varanii (1847) 

 discovered by v. Kolliker ; and two papers, written in 

 conjunction with Lowe, on the presence of cellulose in 

 the test of Tunicata (1846). 



On going to Wurzburg, Prof. v. Kolliker's activity was 

 if anything increased. He almost immediately joined 

 von Siebold in founding the Zeitschrift fiir %uissenschaft- 

 liche Zoologie ; and it is not the least of his claims to 

 the gratitude of biologists that he has continued for half 

 a century to edit this valuable journal. The first numbers 

 contain a series of papers written by himself, of which 

 the following are the most important. 



The essay on Actinophrys recognises the rhizopod 

 nature of this animal, and contains a remarkable dis- 

 cussion of the manner in which rhizopods generally 

 ingest their food. The suggestion is clearly made that 

 the contractile substance of AcHnophrys and Amoeba is 

 identical in nature with that of Hydra and of the higher 

 animals ; so that this paper, and Ecker's paper on the 

 contractile substance oi Hydra which is printed immedi- 

 ately after it, mark an important step in the general 

 conception of what is now called protoplasm. 



The monograph of the Gregarinidce^ also in the first 

 volume, clearly recognises the unicellular nature of an 

 adult Greoarina, and in it i\\& pseudonm'icellcE are stated 

 to represent stages in the life-history of the Gregarina. 

 Many species of Gregarines are described. 

 NO. 1488, VOL. 58] 



[The description of Dicyema (1849) may be most con- 

 veniently referred to here, although it was not published 

 in the Zeitschr.f. w. Zoologie^ 



Of papers relating to vertebrate histology, published 

 in the early numbers of the Zeitschrift, the most im- 

 portant are the memoirs on smooth muscle, and on the 

 skin. In the first the result of the work already referred 

 to is more fully described. This memoir contains a 

 description of the cellular elements of smooth muscular 

 tissue, and a detailed account of its occurrence in the 

 vertebrate body, including a final demonstration of its 

 presence in the walls of the blood-vessels, which was 

 doubted by several anatomists at the time. In the second 

 memoir, the development of the epidermis is described,, 

 and a full account of the development of sweat-glands^ 

 hairs, and sebaceous glands is also given. 



A paper on nerve-cells, and a note upon the distinc- 

 tion between the two classes of cranial bones, according 

 to their method of ossification, must also be mentioned. 



The first published volume of the " Mikroskopische 

 Anatomie," the first of the series of text-books which 

 Prof, von Kolliker has produced, appeared in 1850. This 

 volume was the second of the projected work, and con- 

 tained a systematic account of the various organs, illus- 

 trated by a large series of original figures, many of which 

 have been copied by subsequent writers continuously 

 until the present day. Within two years this was fol- 

 lowed by the celebrated " Handbuch der Gewebelehre 

 des Menschen," translated into English, soon after its 

 appearance, by Busk and Huxley, and again (from a 

 subsequent edition) by Bowman. 



These masterly works are remarkable not only for their 

 complete treatment of adult histology, but for the way in 

 which the development of each tissue is described, when- 

 ever such description is possible, as a means of elucidat- 

 ing its adult structure. The necessity for such a study of 

 the whole history of a tissue, from the &%g upwards, is 

 emphatically dwelt upon in the introduction to the 

 " Gewebelehre." Among points of interest in special 

 sections must be mentioned the whole treatment of the 

 derivatives of the ectoderm (other than the central 

 nervous system), including the development of the sweat- 

 glands, the sebaceous and the mammary glands, and a 

 description of the structure, development and succession 

 of hair, which seems, if an English reader may presume 

 to judge, clearer in some respects than the description 

 given in the Zeitschr. f. w. Zoologie. The relation ' 

 between striped muscles and their tendons is described 

 so as to confirm, by independent evidence, many of the 

 statements of Bowman ; and a special point of interest 

 in the account of muscular tissues is the description of 

 the branched muscle-plates of the heart and certain 

 other organs, which had been described by Leeuwenhoek,. 

 although the description seems to have been forgotten 

 until the rediscovery of the structures by Prof. Kolliker. 

 The chapters on the bones and on the process of ossifica- 

 tion describe the mode of addition to bone beneath the 

 periosteum, and include a detailed description of the 

 growth of bone, together with the ossification of mem- 

 brane bones. These chapters, in which the results of 

 Prof, von Kolliker's researches were shown to be in 

 complete agreement with those conducted in this country 

 by Sharpey, had an important influence upon scientific 



