ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 



297 



c General. 



Influence of Light and Darkness.* — Armand Vire has continued 

 his experiments in the subterranean laboratory in the " catacombs " of 

 Paris, under the Jardin des Plantes. In the darkness, Gammarm 

 fluviatilis exhibited some marked modifications, e.g. gradual disappear- 

 ance of pigment and hypertrophy of olfactory and tactile setae. In an 

 eel, kept in darkness for five years, the eye was almost doubled in 

 volume, though " the optic nervous system " was reduced. Six gold- 

 fish assumed a pale whitish rose colour, and were in two years smaller 

 by a half than a similar number, equally fed, but living in the light. 



Some subterranean animals were kept in the light, e.g. Niphargus 

 plateaui, Vireia burgunda, V. berica, and Proteus anguinus. All showed 

 by their behaviour that the illumination was disagreeable to them, pro- 

 bably through its influence on the pigment-forming cells. After some 

 months, Proteus showed much pigmentation, except beneath the head 

 and belly. The Crustaceans have not as yet shown more than slight 

 black patches on the integument. 



Origin of Primates.f — H. C. Chapman has been led from an 

 anatomical study of Tupaia, in which no caecum was found either in 

 T.ferruginea or in T.pictum, to a speculative essay on the origin of the 

 Primates. His views may be inferred from the following scheme. 



Gorilla Chimpanze 



Homo 



Pithecanthropus - 

 Catarrhinse 



-Gibbon Orang 



Aretopitheca 



Kodentia 



I 



OhiromjB 



Chiroptera 

 Galeopithecus 



Platyrrhiiite 



Lor is 



Insectivora 



I 



Tarsius 



Lemuravidse 

 AdapidsB " 

 Hyopsodinae 



Tegumentary Colorations.} — H. Mandoul has made a very ex- 

 haustive analysis of the types of tegumentary coloration in animals. 

 He distinguishes three, kinds dne to structure : (1) simple reflection, 

 (2) interference, (3) diffraction ; and of pigmentary, intrinsic elaborated 

 within the organism, and extrinsic which are of various origins. Re- 

 flection may give a white colour, or a satin or velvety aspect, and may 

 be due to air, uncoloured liquids or solid pulverulent matter. For 

 interference effects a very thin lamellar structure is necessary, and they 



* Comptes Rendus, cxxxviii. (1904) pp. 706-8. 



t Proc. Acad. Nat. Sci. Philadelphia, 1904, pp. 148-56. 



\ Ann. Sci. Nat., xviii. (1903) pp. 225-468 (2 pis.). 



