ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 167 



pigment in Pleuronectids. Moreover, in metamorphosing young ex- 

 amples the side which is to be pale becomes considerably less pigmented 

 before the fishes swim obliquely or leave their pelagic life. Apart from 

 the influences of light, other factors are operative, — various constitutional 

 peculiarities and the influence of the sympathetic system of nerves. 



Geographical Distribution.* — J. Palacky seeks to show in a learned 

 essay that the territorial mapping of zoo-geographical regions — which 

 will apply to the various phyla — is a hopeless task. Whether the 

 regions be those of Wallace and Sclater, or those suggested by others, 

 they do not fit the facts. The useful task is to take class by class and 

 to correlate their present distribution with what geology has to tell us. 



Phylogeny of Erinaceidse.f — W. Leche continues his splendid work 

 on the evolution of mammalian dentition, with special reference to the 

 Erinaceidse. His results are based on a study of 2G3 skulls and jaws, 

 and on an associated investigation of the other parts of the skeleton 

 and of the soft parts. The outcome is a very important contribution 

 to odontology in general and to the history of the Erinaceida3 in 

 particular. There is an excellent review of the work by M. Furbringer.J 



Throwing-Net and Mud-Sucker. § — 0. Zacharias describes what 

 experience has proved to be a really effective throwing-net for use in 

 plankton work on water-basins that have to be worked from the shore, 

 and also an improved mud-sucker for capturing Rkizopods, Infusorians, 

 and the like. 



Fauna of Alpine Lakes. || — P. Buffa gives a physical and biological 

 account of some alpine lakes of the Trentine mountains. His lists 

 include 12 Protozoa, 23 Rotifers, 7 Crustaceans, and 3 larval Diptera. 



Tunicata. 



Development of Appendicularia.f — R. Goldschmidt notes that there 

 are only two records of observations on this subject, namely, by 

 Kowalevsky and Fol, both to the effect that the development of Appendi- 

 cularia does not differ essentially from that of Ascidians. Goldschmidt 

 studied what were probably the young stages of Oikopleura dioica Fol. 

 The minuteness, the extremely refractive character of the living embryo, 

 and the marked poverty of chromatin in the embryonic nuclei made the 

 investigation very difficult. But he confirms circumstantially what 

 Kowalevsky and Fol said, that the development is in no essential 

 features different from that of Ascidians. 



INVERTEBRATA. 



Mollusca. 

 a. Cephalopoda. 



Nature and Development of Chromatophores.** — Carl Chun has 

 studied the chromatophores in a species of BoliUma (Eledonella), and 



* Verb. Deulscb. Zool. Ges., xii. Vers. (1902) pp. 137-52. 

 t Zoo!o«ica, Heft 37 (1902) 104 pp. (4 pis. and 59 figs.). 

 X Morph. Jahrb., xxxi. (1902) pp. 116-21. 

 § Zool. Anzeig., xxvi. (1903) pp. 201-3. 

 || Atti Soc. Veneto-Trentina Sci. Nat., iv. (1902) pp. 5-32. 

 \ Biol. Centralbl., xxiii. (1903) pp. 72-6 (3 figs.). 

 ** Verb. Deutsch. Zool. Gts., xii. Vers. (1902) pp. 162-82 (11 figs.). 



