Speare: Massospora cicadina Peck 79 



about Washington in 1919, from 50-90 per cent of the male in- 

 sects showing this stage of the fungus during the latter part of 

 the season. 



In its vegetative growth prior to the production of resting 

 spores, the fungus destroys the intersegmental abdominal mem- 

 branes of the host, as it does in the conidial phase of the develop- 

 ment just considered, and there is a similar sloughing off of the 

 abdominal segments. The septum described above, across the 

 body cavity of the insect, which normally persists in insects af- 

 fected with the conidial growth is, however, destroyed in most 

 instances during the formation of the resting spores, and al- 

 though these bodies arise upon the soft tissues concentrated in 

 the last four or five posterior segments of the body, they may be 

 found, owing to the absence of the septum, in some numbers, 

 within the otherwise empty anterior portion of the abdomen. 



The resting spore-mass which is, nevertheless, largely confined 

 to the posterior segments, presents a granular appearance and is 

 of a sulphur yellow color, tinged with green when young, but it 

 assumes a dark brown color when the resting spores are mature. 

 These bodies are less coherent in the mass than are the conidia, 

 and as a result they are scattered about by the movements of the 

 host much more freely. It was in fact not uncommon to observe 

 an infected individual in which the empty body cavity formed one 

 continuous passage from the last abdominal segment to the head, 

 with two or three of its abdominal segments missing, actively 

 crawling or flying about. In this respect the appearance of 

 cicadas showing the resting spores, differs from those showing 

 the conidial growth, because it will be recalled there occurs in the 

 latter a persistent fungus stroma closely associated with the 

 above-mentioned septum, which after the abdominal segments 

 have been dropped, remains as a continuous partition across the 

 abdomen. 



It can therefore be readily seen that, though both of the repro- 

 ductive phases have many characteristics in common, there are 

 nevertheless certain characters by which one phase may be 

 readily distinguished from the other merely by a superficial ex- 

 amination. 



