ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 355 



Photogenic Function in Marine Organisms.* — F. Ales. McDermott 

 uses the argument from analogy (colour and luminescence in beetles) to 

 support the view that the coloration and luminescence of marine 

 organisms must be of use. The absence of definite organs for the re- 

 ception of radiations of light (as in Salpa, the author says !) may not 

 necessarily indicate that the forms from which they are absent are in- 

 sensible to these radiations. " The photogenic functions in certain 

 simple marine forms may replace the olfactory function " (or rather the 

 odoriferous function ?) " of terrestrial forms, to some extent," indicating 

 location. 



Sense of Light in Animals. f — C. Hess finds that fishes react like 

 totally colour-blind men, while Amphibians are like normal men. For 

 birds and reptiles the short-wave end of the spectrum is much shortened ; 

 fowls see up to blue-green, tortoises only to about the green. He finds 

 that caterpillars, midges, flies, seek out the yellow-green part of the 

 spectrum. So do two Crustaceans, Podopsis and Atylus. Cuttlefishes 

 react like totally colour-blind men — indeed, the same may be said of all 

 Invertebrates. Experiments on the siphons of eyeless bivalves showed 

 that red and orange had almost no effect ; the contraction of the siphons 

 was greatest in yellow-green and green, somewhat less in blue and violet. 

 After a period of darkness the adaptive sensitiveness of the siphon is 

 markedly increased. 



INVERTEBRATA. 



Scottish and Irish Plankton.:}: - - W. A. Herdman makes a com- 

 parison of the summer plankton on the west coast of Scotland with that 

 in the Irish Sea, and shows the curious differences between them. For 

 instance, while the abundant vernal phyto-plankton dies away in the 

 Irish Sea in early .summer, a similar micro-flora is present in quantity 

 in some part of the sea on the west of Scotland (e.g. the Sound of Mull, 

 and the sea round Canna, Eigg, etc.) until July, and possibly later. 



Micro-fauna of the Nile.§ — E. von Daday continues his report on 

 the micro-fauna of the Nile. He deals with Protozoa (8), Rotifers (8), 

 Copepods (7), Phyllopods (5), Ostracods (0). Among the last is Aglai- 

 ella stagnalis g. et sp. n., which may be regarded as transitional between 

 Aglaia Brady, on the one hand, and Pontoparta Vavra and Paracypris 

 Sars, on the other hand. 



Mollusca. 



Molluscs of Portuguese East Africa. || — A. Nobre gives a list of 

 the Molluscs collected by Welwitsch, Anchieta, Newton, and others, 

 in Portuguese East Africa, and now deposited in the Bocage Museum, 

 in Lisbon, and elsewhere. 



* Amer. Nat., xlv. (1911) pp. 118-22. 



t SB. Phys. Med. Ges. Wiirzburg (1910) pp. 41-3. 



t Journ. Linn. Soc. (Zool.) xxxii. (1911) pp. 23-38(8 figs.). 



§ SB. k. Akad. Wiss. Wien, cxix. (1910) pp. 537-89 (3 pis.). 



| Bull. Soc. Portugaise Sci. Nat. iii. (1909, received 1911) supp. 2, pp. 1-108. 



