II. PSEUDO-ENTOPHYTA, ETC. 53 



silk-worm, 1 and several species of Splucria and Isaria, which also grow within and 

 upon insects and their larva 1 . 



These fungi grow with great rapidity within the body of the animal they attack, 

 not only at the expense of the nutritive liuids of the latter, but, after its death, all 

 the interior soft tissues appear to be converted into a solid mass of mycelium, from 

 which arise one or more aerial receptacles of the spores. 



I once found a specimen of Gryllo-talpa americana, sitting at the mouth of a 

 hole beneath a log, apparently in perfect health, but, upon nearer examination, 

 found it had been so completely invaded by a fungous mycelium that even the joints 

 of the tarsi were distended with it. 



The same kind of fungous substance I have observed distending the bodies of 

 larvae of several species of our indigenous lepidoptera, and once, also, the larva of a 

 lamellicorn insect. 



Of a closely analogous character is a fungus which I found to be very common in 

 the seventeen-year locust, Cicada septendecim, under the following circumstances : 



In a number of the female insects, within the vagina and projecting externally, 

 I frequently observed a moist, white, filamentous substance, which I supposed to 

 be spermatic matter, but, upon examination, found to be composed of a mycelium, 

 of fungous filaments (PL X. Figs. 27, 28). Most of these were branching, inar- 

 ticulate, from the -9 oV'o to the -g-g'W of an inch in diameter, and were filled with a 

 hyaline protoplasma, with an occasional isolated yellowish granule. Others were 

 united to several oblong cells, or were continuous with what appeared to be the 

 original spore, and contained a protoplasma, and hyaline amorphous globules. 

 With the filaments were intermingled numerous round or oval spore-like bodies, 

 from the TT V U to the -, -^-^ of an inch in diameter, colorless, and with hyaline 

 granular contents and one or several nuclei (29). 



In the spring of 1851, during the imago appearance of the seventeen-year locust, 

 among myriads of the insect, several friends and myself found between 12 and 20 

 specimens, which, though living, had the posterior third of the abdominal contents 

 converted into a dry, powdery, ochreous-yellow, compact mass of sporuloid bodies. 

 The caudal appendages and posterior two or three abdominal rings covering the 

 mass, were loose and easily detached, leaving the fungoid matter in the form of a 

 cone, affixed by its base to the unaffected part of the abdomen of the insect. 



The sporuloid bodies, which constituted the entire mass, were oval or ovate in 

 form, with a wrinkled surface, and faintly granular contents, and measured from 

 the ^--gVo- to the ^^ of an inch long, by the ^-^ to the ^ 5 ^ of an inch broad. 



From the observations thus made upon the fungous disease of the seventeen-year 

 locust, it is probable the insect is more liable to it than we can have any means of 

 estimating. The fungus may commence its attack upon the larva of the insect, de- 

 velop its mycelium, and produce a sporular mass within the active chrysalis, while 

 ascending and descending its chimney to receive full benefit from the air, and in 



1 Eighteen years ago, a younger brother and myself, for our amusement, reared several thousand silk- 

 worms, among which we often observed and carefully removed what we then called "mouldy silk-worms," 

 or "silk-worms affected with the mould disease." 

 8 



