THE BEGINmNGS OF LIFE. 



355 



certain that in this affection — named ^ pebrine ' on 

 account of the black spots which are produced on the 

 skin — Psorosperms of the simplest description abound 

 in almost every organ and tissue of the affected worms 



It 



m 



ir 



-Fi=^j 



fc^^ 



©^ 



:m 







Fig. 74. 

 Psorosperms and their Mode of Development. (Balbiani.) 



a, a. Psorosperms from the Silk-worm. 

 b, b, and c, c. Rare and occasional varieties of these. 



X, y. Psorosperais in an earlier stage of development, which are 

 found intermixed with the more perfect forms. ( X 1 700.) 



M, s. Portion of the intestine of a small Caterpillar {Gastro- 

 pacha), showing masses of Psorosperms in different 

 stages of development beneath the serous coat. At 

 first, mere homogeneous masses of matter (p, p) appear, 

 in the midst of which Psorosperms are developed after 

 the manner of nuclei. ( x 250.) 



or moths. Whether they are causes of the disease, 

 however, or are mere concomitant products, really 

 occasioned by a previous blood-change (and therefore 

 comparable with the fungi in muscardine), it is im- 

 possible for us to say: though it is certain, from the 

 A a 2 



