THE PARASITIC FUNGI OF INSECTS. 75 



detached and spherical cells are formed by repeated sprouting 

 from the germ tube, which has penetrated through the skin into 

 the interior cavities of the insect, and each cell as the insect dies 

 develops into' a long tube containing much protoplasm. This 

 tube pierces the skin, grows outside it into a short club-shaped 

 body, at the end of which is produced a single spore. This club- 

 shaped body, or basidium, is connected with the spore by a 

 narrow neck, and at this point is formed a cross-septum separating 

 the one from the other. The membrane of the basidium is 

 highly elastic, but its cohesion is less over an annular zone 

 immediately beneath the cross-septum, than at any other part. 

 The consequence is that, as tension increases, consequent on the 

 continuous absorption of moisture by the basidium, there comes a 

 time when it overcomes the resistance of the less coherent 

 annular zone, the wall opens by a circular fissure, the pressure is 

 at once relieved, and the elastic wall of the basidium contracts, 

 especially in the direction of the transverse diameter, and this 

 causes a large quantity of the fluid contents of the basidium to 

 be squirted out with great force through the fissure^ striking full 

 on the transverse septum, and carrying the spore with it. Some- 

 times in Empusa the ripe spores are thrown to a distance of 3 cm., 

 and adhere by the remains of the ejected protoplasm to the bodies 

 against which they strike. 



These spores, or conidia, emit a germ-tube, which is capable of 

 penetrating at once into the body of a suitable host, and so 

 repeating the process of development already described. If 

 supplied with sufficient moisture the spores produce short tubes, 

 from the extremities of which secondary spores, or conidia, are 

 produced, capable of undergoing the same development as the 

 primary ones. These spores, or conidia, preserve their power of 

 germinating during a period of about fourteen days. 



In Entomophthora, numerous branches of the entozoic 

 mycelium appear on the surface of the body of the insect it has 

 killed, and there ramify in so copious a manner that they soon 

 wrap it in a close felt. At the end of each of these ramifications 

 a spore, or conidium, is formed just as in the manner described in 

 Empusa, and is thrown off in the same way by abjection, as it is 

 called. 



