41 6 Journal of Agricultural Research voi. xvui. No. s 



adapted for reproduction in a liquid menstruum such as insect blood, 

 the circulation of which carries them to all parts of the body cavity and 

 continually supplies them with fresh nutriment. 



Thaxter (21) in 1888 showed that in certain cases at least the vege- 

 tative development of the entomogenous Entomophthorales was carried 

 on not by branching hyphae, but by "hyphal bodies" which consisted of 

 short, thick fragments of irregular size and form that reproduced by 

 budding, a phenomenon analogous to that described above, though the 

 blastocysts of Sorosporella are regularly elliptical and symmetrical in 

 form. 



Because of the similarity of the blastocysts to yeasts and in certain stages 

 even to sporozoans, considerable confusion might result and erroneous 

 conclusions be reached if subsequent stages in the development of the 

 fungus were not known ; and in fact so anomalous in character were the 

 blastocysts that considerable care was taken to prove their identity with 

 Sorosporella. 



In the course of the cultural experiments described below, it was found 

 that when Uschinsky's solution was inoculated with Sorosporella, a type 

 of yeastlike cell was produced that is quite comparable with that found 

 in the blood of insects. This similarity will at once be evident by com- 

 paring Plate 53, B, with Plate 53, A. The former is a photomicrograph 

 of the blastocysts produced on Uschinsky's solution and was made from 

 a water mount, while the latter is from the blood of an infected insect 

 and was made from a slide stained in Erlich's haematoxylin and eosin. 



In order to obtain further evidence, however, single blastocysts were 

 removed from the blood of an infected insect by means of Barber's 

 pipette holder and were transferred to nutrient agar. 



A small area on the abdomen of an infected insect was washed in 

 alcohol, after which a sterile capillary tube was inserted into the body, 

 and a small amount of blood together with a number of blastocysts was 

 collected. The tube was then removed and its contents ejected upon an 

 inverted sterilized glass slide placed upon a suitable holder on the stage 

 of the microscope. Examination of the drop of blood was then made 

 with the microscope. A place was chosen where a small number of 

 blastocysts occurred, and another sterile capillary tube fastened to 

 Barber's holder was adjusted in such a way that only a few blastocysts 

 were drawn into it. These blastocysts were ejected upon the slide at 

 another place and the process repeated until only one blastocyst was 

 drawn into the tube. This single fungus cell was then ejected upon a 

 hanging drop of culture medium, and a pure growth of Sorosporella 

 resulted. 



The operation, though requiring a certain amount of care, was not 

 especially difficult in the present instance, because no extraneous organ- 

 isms were found in the blood to interfere, and because the blastocysts, 

 which are large, are readily visible and easy to manipulate. 



