Contagious Diseases of Insects. 297 



usually in singles and doubles, the spherical ones commonly in 

 doubles and short chains of four to six ; in the latter case, 

 often taking on a quadrate form. The ovals varied in length 

 from 1 p to 1.4 /*, and in transverse diameter from .8 /* to 1 P. 

 The spherical and quadrate forms were nearly always under 

 1 i* in diameter, usually averaging about .8 /*. Both forms 

 stained readily with both methyl violet and brown, and occurred 

 frequently in patches or colonies in the intestinal canal. 



T mention here a point of especial interest in relation to 

 subsequent attempts at culture and infection. I studied on the 

 morning of the 5th August the fluids of a larva which had died 

 during the night. The blood obtained by snipping a proleg 

 was thick and gray with bacteria, as were also the intestinal 

 fluids, many in both blood and alimentary canal having the 

 form and flagellate movement of Bacterium. Occasionally a 

 string of four, attached end to end, would be seen in serpentine 

 movement across the field. Well-stained and permanently 

 mounted slides of their fluids show three bacterial forms: one 

 large oval, undoubtedly Bacterium termo; one a smaller oval 

 (the Micrococcus already described); and the third a somewhat 

 peculiar oval form which might be understood as a single oval 

 1.5 p. long, with a pale center, or as a short double oval whose 

 division was indicated, not by indentations of its margins, but 

 by a thinning of its central part. The study of slides subse- 

 quently made under other circumstances enables me to say that 

 this form last mentioned is really a developing Bacillus of a 

 peculiar character which, matured, is short, broad, and quadrate, 

 its central portion pale when stained, and the ends contrasting 

 by a positively darker tint. Unable to identify this form with 

 anything described, or to obtain through my botanical friends 

 any specific determination of it, I shall refer to it in this paper, 

 merely for convenience sake, under the provisional name of 

 Bacillus intrapallens* 



*I do not know that this is a distinct species, or intend so to 

 imply. Bacillus subtilis sometimes presents the peculiar segregation 

 of its contents here described, under what peculiarities of circum- 

 stance I do not know, but never, as far as I have observed or can 

 learn, until the full size of the cell has been reached. In the above 

 Bacillus, on the other hand, it was usually evident as soon as the 

 young cell was large enough to show it. 



