ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 713 



the peculiar choanse of Dermochelys coriacea, and throw light on the 

 evolution of the Athecae from the marine Thecophora. 



In a subsequent essay * Hollo discusses the origin of Dermochelys, 

 and seeks to interpret the osteology of Chelonians in terms of the 

 myology and ethology. He tries to realise the ethology of the extinct 

 types, and discusses the geographical and strati graphical distribution, 

 and the classification of Chelonia. He uses his results as a basis for 

 some general etiological suggestions. 



& v 



Classification of Trionychidas.t— Fr. Siebenrock takes a survey of 

 this family of Chelonians, and uses the structure of the various parts of 

 the plastron as a basis for a revised classification. He also describes % 

 Cyclanorbis oligotylus sp. n. In another paper he revises the classifica- 

 tion of the species of Podocnemis. 



Origin of Poison Glands in the Land Salamander. §— M. Phisalix 

 finds that the first appearance of the cutaneous glands is not due to a 

 proliferation of the cells of the deep layer of the epidermis ; it is in the 

 dermis, under the basal layer of the epidermis, that the first rudiments 

 of the poison glands appear. They are thus mesodermic in origin, and 

 connections with the ectoderm and the formation of their ducts con- 

 stitute secondary phenomena. 



Sense of Hearing in Fishes. || — G-. H. Parker shows that the common 

 killifish, Fundulus heteroclitus, does actually hear sounds made by tuning- 

 forks, and that it becomes deaf if the auditory nerve be cut. 



The lateral line is closely associated with the ear, and may also assist 

 in hearing. In the skin, the lateral line, and the ear, we are dealing 

 with what may be called three generations of sense-organs ; the skin 

 representing the first generation, and giving rise to the lateral line organs, 

 the second, which in turn produce the ears. 



Change of Colour in Trout. f — Albert Schondorff has made many 

 experiments, and comes to the following conclusions. The colour-change 

 is wholly due to the persistent migration of the ehromatophores and to 

 their expansion or contraction. The chief factor is the influence of illu- 

 mination ; a direct nervous role was not proved. 



In the trout there are only two kinds of pigment, namely, melanins 

 and lipochromes. The former occur in rods, and are intracellular ; the 

 latter are amorphous and extracellular. In the ehromatophores the 

 pigment-cells and their processes form a structural and functional unity, 

 that is to say, the melanin-rays are processes of the pigment-cells, and 

 disappear when the latter contract. 



The author contradicts the conclusion that no pigment-cells occur 

 in the epidermis. His figures show that apart from processes the bodies 

 of the pigment-cells occur in the epidermis. The origin of the epidermic 



* Tom. cit., pp. 801-50. 



t SB. k. Akad. Wi.-s. Wien, cxi. (11)02) pp. 807-46 (18 figs.), 

 t Tom. cit., pp. 157-70 (1 pi.). 



§ Arch. Zool. Expe'r., series 4, i. (1903). Notes et Revue, No. 8, pp. cxxvi-cxl. 

 |j Bull. U.S. Fish Commission for 1902, pp. 45-64(1 pi.). See Amer. Naturalist, 

 xxxvii. (1903) pp. 499-500. 



% Arch. Naturges., lxix. (1903) pp. 399-426 (1 pi.). 



