258 



NA TURE 



{Feb. 5, 1874 



From the lowest animals, he has gradually extended 

 his investigations up to the highest, and even to man. 

 His earlier labours were, for the most part, occupied with 

 the lower marine animals, especially with the pelagic 

 organisms swimming at the surface of the open sea. He 

 availed himself of an excellent opportunity for the study 

 of these, when on board H.M.S. Rattlesnake on a 

 voyage of circumnavigation, which took him to many 

 most interesting parts of tropical oceans little investigated, 

 previously, by the zoologist ; especially the coasts of 

 Australia. Here he was able to observe, in their living 

 state, a host of lower pelagic animals, some of which had 

 not at all been studied, others but imperfectly. In the 

 Protozoa, he was the first to lead us to satisfactory con- 

 clusions concerning the nature of the puzzling Thalas- 

 sicoUidffi and Sphserozoida. Our knowledge of Zoophytes 

 has be n greatly extended by his splendid work on 

 " Oceanic Hydrozoa," in which, chiefly, the remark- 

 able S phonophora, with their largely developed poly- 

 morphism and the instinctive division of labour in their 

 individual organs, are described with very great 

 accuracy. 



Already in his first work " On the Anatomy and the 

 Affinities of the Medusa;," 1849, he directed attention to 

 the very impoitant point, that the body of these animals 

 is constructed of two cell layers — of the Ectoderm and 

 the Endoderm— and that these, physiologically and mor- 

 phologically, may be compared to the two germinal 

 lajers of the higher animals. He has made us better 

 acquainted with several interesting members of the class 

 Vermes, Sagitta, Lacinularia, some lower Annulosa. &c. 

 He was the first to point out the affinities of Echino- 

 deimatawith Vermes. In opposition to the old view, that 

 the Echinodermata belong to the Radiata, and, on 

 account of their radial type, are to be classed with corals, 

 medusae, &c., Huxley showed that the whole organisation 

 of the former is essentially different from that of the 

 latter, and that the Echinoderms are more nearly relatedi 

 morphologically, to worms. Further he has essentially 

 enlarged our knowledge of the important group of 

 Tunicata by his researches on the Ascidians, Appendicu- 

 laria, Pyrosoma, Doliolum, Salpa, &c. 



Many important advances in the morphology of the 

 Mollusca and Arthropoda are also due to him. Thus, e.g., 

 he has greatly elucidated the controverted subject of 

 the homology of regions of the body in the various classes 

 of Mollusca. He has considered the generation of vine- 

 fretters from quite a new point of view, based on his 

 " genealogical conception of animal Individuality." But it 

 is the comparative anatomy and classification of the Verte- 

 brata which, during the last ten years, he has especially 

 studied and advanced. His excellent " Lectures on the 

 Elements of Comparative Anatomy " afford abundant 

 proof of this, to say nothing of his numerous important 

 monographs, especially those on living and extinct fish, 

 amphibians, reptiles, birds, and mammals. 



Huxley's works on the comparative anatomy of the Verle- 

 brata are the only ones which can be compared with the 

 otherwise incomparable investigations of Carl Gcgenbaur. 

 These two inquireis exhibit, particularly in their peciiliar 

 scientific development, many points of relationship. They 

 both belong to that small circle of morphologists which is 

 marked by the names of Caspar (.Friedrich Wolff, George 



Cuvier, Wolfgang Goethe, Johannes Miiller, and Carl 

 Ernst von Baer. 



More important than any of the individual discoveries 

 which are contained in Huxley's numerous less and 

 greater researches on the most widely different animals 

 are the profound and truly philosophical conceptions which 

 have guided him in his inquiries, have always enabled him 

 to distinguish the essential from the unessential, and to value 

 special empirical facts chiefly as a means of arriving at 

 general ideas. Those views of the two germinal layers of 

 animals which were published as early as 1849 belong 

 to the most important generalisations of comparative 

 anatomy ; they already contain in germ, the idea of the 

 " perfect homology of the two primary germinal layers 

 through the whole series of animals (except protozoa)," 

 which first found its complete expression, a short 

 time since, in the " Gastrasa theory;" also his re- 

 searches on animal individuality, his treatment of the 

 celebrated vertebral theory of the skull, in which he first 

 opened out the right track, following which Carl Gegen- 

 baur has recently solved in so brilliant a manner this 

 important problem, and above all his exposition of the 

 Theory of Descent and its consequences, belong to this 

 class. After Charles Darwin had, in 1859, reconstructed 

 this most important biological theory, and by his epoch- 

 making theory of Natural Selection placed it on an 

 entirely new foundation, Huxley was the first who ex- 

 tended it to man, and in 1863, in his celebrated three 

 Lectures on " Man's Place in Nature," admirably worked 

 out its most important developments. With luminous 

 clearness, and convincing certainty, he has here estab- 

 lished the fundamental law, that, in every respect, the 

 anatomical differences between man and the highest apes 

 are of less value than those between the highest and the 

 lowest apes. Especially weighty is the evidence adduced, 

 for this law, in the most important of all organs, 

 the brain ; and by this, the objections of Prof. Richard 

 Owen are, at the same time, thoroughly refuted. Not only 

 has the Evolution Theory received from Prof. Huxley a 

 complete demonstration of its immense importance, not 

 only has it been largely advanced by his valuable com- 

 parative researches, but its spread among the general 

 public has been largely due to his well-known popular 

 writings. In these he has^accomplished the difficult task 

 of rendering most fully and clearly intelligible, to an 

 educated public of very various ranks, the highest 

 problems of philosophical Biology. From the lowest to 

 the highest organisms, from Bathybius up to man, he has 

 elucidated the connecting law of development. 



In these several ways he has, in the struggle for truth, 

 rendered Science a service which must ever rank as one 

 of the highest of his many and great scientific merits. 

 Ernst Haeckel 



ZOOLOGICAL NOMENCLATURE 

 The Object and Method of Zoological Nomenclature. By 

 David Sharp. (E. W. Janson and Williams and Nor- 

 gate, 1873.) Pp.39. 



ZOOLOGISTS and botanists universally adopt what 

 is termed the binomial system of nomenclature in- 

 vented by Linnaeus. The essential principle of this sys- 

 tem is, that every species of animal or plant is to have a 

 name made up of two words, the second word — which is 



