No. 443-] NOTES AND LITERATURE. 



shows six, the usual number for the cat. Defects of this kind are 

 too frequent to make the book really useful in the hands of most 

 beginners. 



Notes. — The action of light on organisms and the production of 

 light by organisms are presented in readable form by R. Dubois in 

 the second volume of the Traitt de Physique Biologigue. The effect 

 of light on the action of enzymes, on the production and destruction 

 of pigments, and on the circulation and respiration of the higher 

 animal is described at some length. The influence of light on the 

 movements of animals is very inadequately treated probably because 

 most of the researches on this subject have come from other than 

 French laboratories. Dermatophic vision and its relation to vision 

 by means of eyes is fully discussed from the standpoint of Pholas. 

 The production of light by organisms forms a brief, compact essay 

 dealing with the photogenic bacteria, the light-producing protozoa, 

 insects and mollusks. It contains interesting statements of the rela- 

 tive energy values of living and mechanical sources of light and is 

 illustrated by some remarkable photographs taken by light from liv- 



chemical, light, and heat rays. 



A brief account of the structure of the rudimentary eyes in the 

 Cuban blind snake, Typhlops lumbricalis, has been published by 

 E. F. Muhse in the Biological Bulletin, Vol. V, xVo. 5, 1903- 

 eye appears as a dark spot surrounded by an unpigmented circle 

 and covered by a large ocular scale. Internally the usual parts 

 can be distinguished including a well-developed lens and a retina 

 in which the layers typical for snakes can be seen. 



R. Dubois last year reported to the French Academy of Sciences 

 and to the Society of Biology the success of his experiment to 

 acclimatize true pearl oysters on the French 



methods 



producing small but high grade \ 

 under natural conditions it was 

 oysters to obtain one pearl. 



C. H. Eigenmann and C. 1 

 Biological Bulletin call attention 

 the cave salamander, Spelerpes m 

 Titicaca with a branched left barl 

 haniphus with an additional left a 



oyster; 



from Lake 

 of Xiphor- 



