Contagions Diseases of Insects. 883 



number of large, regularly elliptical bodies, about 5 /* in length 

 by 3 ;U in transverse diameter. As they do not stain, they are 

 probably crystalline, especially as it is well known that larvae 

 about to moult or pupate often have the blood loaded with crys- 

 tals of uric acid of which the form is often not different from 

 that here noted. 



As characteristic of the second form of disease, flacherie^ 

 that distinguishable in the living larvae by the pale color of the 

 surface as compared with the lemon-yellow of jaunes, I have 

 selected slide 4727. derived from the fluids of a freshly dead 

 larva. In the blood of this specimen no bacteria were discern- 

 ible, but in this slide, prepared from the mingled blood and 

 alimentary fluids, they occur in innumerable myriads. The 

 slides are, however, instantly distinguishable from those derived 

 from the yellow-skinned larvae, by the complete absence of the 

 mulberry granules. The bacteria from the selected slide are 

 not by any means so uniform as those in the one previously 

 described, but vary from perfectly spherical micrococci to ovals, 

 double ovals, and elongate bacillar rods. The spherical and 

 oval forms of micrococci are, however, the predominant bac- 

 teria. The spheres in this slide are commonly wider than the 

 ovals, measuring about .75 fi, while the smaller ovals are not 

 more than .5 ft in their short",er diameter. The spheres vary in 

 arrangement from singles to chains of considerable length, but 

 the latter aggregates may be due to an accidental running 

 together in the drying film. The bacilli are not distinguishably 

 different from those described for the other form of disease. 

 Besides the above, occasional larger broad ovals appear, similar 

 to those doubtfully determined above as Bacillus intrapallens. 

 Judging, in short, from this representative slide, one would 

 say that the bacteria of Jiacherie of the silkworm consist of a 

 varied mixture of round and oval micrococci of different sizes, 

 of species of bacteria, and of small bacilli. Some of them, how- 

 ever, may have been of pout mortem origin. The slide in ques- 

 tion is beautifully stained with methyl violet, and mounted in 

 dammar. 



