ZOOLOGY. 335 



phosplioresceut at ordinary temperatures are uot numerous, and the one 

 which chiefly occurs is jihosphui-eted hydrogen. This, M. Jousset de 

 Bellesmeis led to believe, is the case in the glowworm, and he is influ- 

 enced in his opinion by the extreme resemblance observable between the 

 phosphorescence of substances in decomposition which is due to the 

 evolution of phosphureted hydrogen and that of luminous animals. They 

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

 for oxygen, the only difference being that the cadaveric i)hosphorescence 

 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 takes place in animals of high organiza- 

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

 mals {e. (). — Noctiluca') only by means of ext^irnal excitants. 



The author has been led by his investigations to regard phosphores 

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

 phosphureted hydrogen. 



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

 destitute of a nervous system, are phosphorescent, and has the addi- 

 tional advantage of connecting the phenomena of phosphorescence 

 observable in living animals with those exhibited in organic matters in 

 course of decomposition. It is, he concludes, another exami)le 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 Pleasonton recorded 

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

 the obser\'ations 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 ma^^le the subject during the past year of special 

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

 were placed in vessels and covered with glasses or fluids of diiferent 

 colors. "At first the developmental i)rocesses did not differ among 

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

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

 exposed to red light rotated most rapidly, whUe great torjjor was 

 exhibited by those under the blue glass ; the rest, exposed to yellow or 

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

 glass. " The most greedy w^ere 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 



* Moleschott aud Fubiui. Jour. Hoy. Alicr. Soc, vol. ii, pp. 138, 273, and vol. iii, p. 

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

 Comptes Bendiis Acad. Sci. Paris, vol. xci, pp. 440, 441. 



