ENTOMOPHTHOREAE OF THE UNITED STATES. 191 



mtiive. Of these spores there are two kinds usually to be seen in preparations: a larger 

 form nearly resembling an Enqnisa conidium and possessing a perfectly smooth outer 

 wall (fi<^s 421-423) ; and a second form, thicker walled, smaller, distinctly papillate in 

 most instances, but produced similarly from hyphal bodies (figs. 421-428) . The devel- 

 opment of these spores after formation is wholly unknown, although there can be little 

 doubt that they furnish the immediate means of spreading the disease. It should be 

 noted that the anterior portion of the host's body is wholly free from fungus in the spec- 

 imens which I have examined. The host may thus live for a considerable time after the 

 abdominal rings have begun to fall away and in this manner disseminate the spores by its 

 own movemeirts. That this is the fact seems certain from the observations of Professor 

 French who writes me that he has seen both larvae and imagos of the locust moving 

 about at Carbondale, 111., in the condition just described. The probable development of 

 the spores after falUng from the host may be inferred from analogy with Empusae gen- 

 erally and would naturally consist in the production of secondary conidia discharged as 

 in' Empusae, and affording the direct means of infection. The smaller type of spore 

 from the considerable thickness of its walls is manifestly adapted to await uninjured the 

 occurrence of conditions favorable to its germination and the hypothetical course of de- 

 velopment given above would thus result in a dissemination perhaps quite as effectual as 

 in the usual course adopted by Empusae. ., -, . -r, i 



I have included as " resting spores " a second type of spore described by Peck as oc- 

 ciu-rino- in certain individuals, although never having seen these spores I am unable to 

 determine whether I am right in so doing. The description quoted gives no note of 

 either their shape or origin, so that I am only justified in considering them resting spores 

 from their analogy to similar spores in j;/»^jwsa. , ^ ,, . i p .i r . 



The distribution of the species is apparently wide, and a further study of the facts 

 connected with its history and development should be full of interest. Whether the fun- 

 gus is adapted to a subterranean existence, attacking the larvae during their seventeen 

 years of existence and thus appearing subsequently on the fully developed host, or whethei- 

 it is continued for this long period by resting spores (a supposition highly improbable), 

 or by the infection of isolated specimens of the same or nearly allied hosts which continue 

 the infection during this period, is quite uncertain. It is apparently liable to appear 

 wherever the Cicada is known, as shown by the localities above mentioned. I am m- 

 debted to the kindness of Mr. L. O. Howard for specimens received from Michigan which, 

 together with an example in Dr. Farlow's herbarium from Texas are the only specimens 

 wliich I have examined.^ 



BaSIDIOBOLUS Eidam (1885). 



Basidiobolus Ranarmn, Eidam I. c. Schroeter Z. c, p. 224. 



Conidia nearly spherical to subovoid, tapering slightly to a rounded base fi'om which 

 the small sharply pointed papilla of attachment projects abruptly. Average measurements 



. The above was iu press before the author had seen the in which he places the present genus among the Ento- 

 excellent summary of contagious insect diseases by Prof. mophthoreae. 

 S. A. Forbes (Psyche, Vol. v, pp. 3-12, Cambridge (1888)), 



