306 Illinois State Labomtori/ of Natural IJistorij. 



Examined June 29, at nine o'clock a, m., the fluid obtained by 

 snipping off a prolegjWas found swarming with large bacilli, 

 motionless at fii'st, but beginning to move actively in all direc- 

 tions when exposed to the air under the cover. These bacilli 

 measured from 2.5 /* to 5 a* in length, one apparently undivided 

 reaching a length of 8 fi, with a transverse diameter of 1.5 i*. 

 These presented no appearance of spores; the ends were broadly 

 rounded, the sides parallel. Small numbers of micrococci 

 occurred in the same slides, about .7 ^i in diameter, strictly 

 spherical, in singles and doubles. An examination of carefully 

 stained slides leavesjlittle room for question of the identity of 

 these bacilli with some of 'those introduced with the food, but 

 the interval jv/as too ^ short to make it certain that they had 

 multiplied since ingestion. Their occurrence, however, in such 

 vast numbers in the blood so soon after death, makes it very 

 unlikely that they merely represented an escape of the intes- 

 tinal fluids, especially as we shall soon see that the same bacilli 

 occurred abundantly in the blood of larvas not yet dead. The 

 intestinal contents were full of the above Bacillus and the 

 usual Micrococcus, 1 ;it in diameter, in singles, doubles, and 

 patches. The food contents were partially digested. 



Besides the above bacteria, the blood was yellow with 

 masses of cells w^ith granular contents, many with a large 

 nucleus each. These cells were apparently derived from the 

 fatty bodies, which seemed to be in process of disorganization, 

 but differed from the usual mulberry bodies which result from 

 pupal histolysis, by the fact that there was no appearance of 

 the division of the cell contents into mulberry granules. 



Another larva observed this day, June 29, evidently torpid 

 and apparently sick, seemed to have moulted imperfectly, frag- 

 ments of the skin still clinging to the shrunken posterior seg- 

 ments. The body was flaccid, but not discolored. A proleg 

 being snipped off, no flow of blood followed, but the fluid pressed 

 out contained a moderate number of the above bacilli, no 

 micrococci, but many well-defined mulberry cells and 

 granules. Each of the cells contained from ten to fifteen 

 or twenty of the latter. The alimentary contents contained 

 micrococci with an occasional Bacillus, but none of the mul- 

 berry granules, both forms of bacteria being in this larva much 



