ZOOLOGY. 



335 



l^liosplioresceut at ordinary temi^cratures are not numerous, aud tlie one 

 wbicli chiefly occurs is phospbureted hydrogen. This, M. Jousset de 

 Bellesmeis led to believe, is the case in the glowworm, aud be is influ- 

 enced in bis opinion by the extreme resemblance observable between the 

 lihosphorescence of substances in decomposition which is due to the 

 evolution of phospbureted hydrogen and that of luminous animals. They 

 present, he thinks, the same physical characteristics, the same affinity 

 for oxygen, the only ditt'erence being that the cadaveric phos])horescence 

 is continuous, while the phosphorescence of animals is intermittent. 

 But the latter is due to the fact that the cellular decomposition which 

 sets free the luminous product tak es place in animals of high organiza- 

 tion only under excitation of the nervous system, and in the lower ani- 

 mals {e. (J. — Noctilucw) only by means of external excitants. 



The author has been led by his investigations to regard phosphores 

 cence as a general property of protoplasm consisting in the evolution of 

 phospbureted bj'drogen. 



This view readily explains why many of the lower animals, although 

 destitute of a nervous system, are j^bosphorescent, aud has the addi- 

 tional advantage of connecting the phenomena of i)hosi)horescence 

 observable in living animals with those exhil.i . d in organic matters in 

 course of decomposition. It is, he concludes, another example of a 

 biological phenomenon very closely related to an exclusively chemical 

 cause. 



LIGHT AND ITS EFFECTS ON ANIMALS. 



It may be recalled that some years ago General Pleasoutou recorded 

 some startling ideas with respect to the mflueuce of blue light. As 

 the observations were evidently made in a very crude fashion, little 

 attention was paid to them. The subject of the influence of different 

 colored rays has been made the subject during the past year of special 

 investigation by Moleschott and Fubini.* The eggs of a frog and toad 

 were placed in: vessels and covered with glasses or fluids of different 

 colors. "At first the developmental processes did not differ among 

 the different ova, or from those which were exposed to ordinary day- 

 light." When rotation commenced, however, it was found that the eggs 

 exposed to red light rotated most ra^ndly, while great toriwr was 

 exhibited by those under the blue glass ; tlie rest, exposed to .\ellow or 

 green light, did not differ at all from those developed under uncolored 

 glass. " The most greedy were those under the blue glass. When 

 brought from their artificial influence, its effects gradually passed off. 

 When changed from one color to another, the activity displayed became 

 gradually more or less." In investigating the action of different kinds 



* Molescliott aud Fubini. Jour. Boy. Micr. Soc, vol. ii, pp. 138, 273, and %'oi. iii, p. 

 409. Also, E. Yung, on the influence of colored light on the development of animals. 

 Compies Itendus Acad. Sci. Paris, vol. xci, pp. 440, 441. 



