436 Agricultural Experiment Station, Ithaca, N. Y. 



ments made to infest tlie Cleonus larvte were eminently successful. 

 Of ninety larvae, which for a short time were brought in contact 

 with the spores, sixty-two died from Muscardine within twelve 

 days. On the imago of the Cleonus, the Muscardine acts somewhat 

 more slowly, but just as surely. Of fifty-eight beetles which he 

 infected when fresh from the pupa, fifty-two died from Muscardine 

 within fifteen days. From these and other experiments. Professor 

 Metchnikoff concludes that Isaria destructor produces an epizootic 

 disease of the insects mentioned, and believes it possible to produce 

 the disease by sowing the spores. 



ISAEIA DENSA (Link.) Fries. 



A pure culture of this fungus was obtained from Fribourg and 

 Hesse, Paris. In describing the appearance of insects killed by the 

 fungus, Giard says that the fungus appears in nature under very 

 characteristic forms. In dry places the bodies of white grubs are 

 hard and covered with a sparse white down which becomes pul- 

 verulent as the age becomes greater. In moist and clay soil the 

 fungus sends out irregular prolongations from 5 to 6 cm. or even 

 more in length. These prolongations cement the particles of earth 

 and roots of vegetation, Tliey often stretch from one mummy to 

 another. He speaks of these prolongations as sporophores, com- 

 paring them to the aerial sporophores of the other Isarias. Both 

 are sometimes sterile and sometimes fertile, and both are usually 

 preceded by an enveloping stage. He ends by saying that the dif- 

 ference between the Isaria of the June bug, and the other Isarias 

 is of the same nature as the difference between an aerial stem and a 

 rhizome in the Phanerogamia. 



A dilution culture was made from the pure culture obtained from 

 Paris, and the following characteristics of growth noted. Germina- 

 tion begins after about two days. The conidia become swollen and 

 put out two or three germ-tubes (Fig. 23.) Soon the oval vacuoles 

 become abundant and a few septa appear. After about four days 

 the threads become full of large vacuoles (Fig. 25). The threads 

 now become irregular in size. Some are large and inflated, the 

 small ones are usually tapering and constricted at the base (Fig. 29). 

 Elongate spores are thrown off in the agar, from the ends of short 

 branches. The colonies are at this time finely radiated, and about 3 

 mm. in size. In a week's time many strands are to be seen, formed 



