EXTOMOGENOUS FuNGI. 435 



of the surface. The felt produced is much less elevated. After 

 about two weeks the dull sage green color appeared quite perceptibly 

 in the variety americana. In Isaria anisopliK the dark bottle- 

 green color appears somewhat earlier. The growth of Iscnna 

 anisoplioe subsequently spreads over the entire surface of the 

 potato. Isaria anisopli(£ has a very dense, farinaceous appearance, 

 while the variety has a looser cottony one. The color of Isaria 

 anisoplicB is a deep brownish bottle-green, with the color of the 

 mycelium distinctly green where it touches the glass. The color 

 of the variety americana on the other hand is dull sage-green, with 

 the mycelium buff yellow. These characters have been constant 

 during a long series of cultures. 



Krassilschik speaks of the coremium-form which sometimes 

 appears on potato cultures. This is produced as follows : the 

 branches of the mycelium bear in old cultures a dense crust of 

 conidia having a columnar structure. Now small isolated patches 

 of conidia-bearing mycelium often produce a small mass of conidia 

 which cling together, producing small pieces of crust having this 

 coluninar structure, and sometimes showing the white mycelium 

 beneath. This method of growth resembles Coremium quite 

 closely but differs from the typical coremium method of growth.. 

 Professor Metchnikoff gives a short abstract* of his investigations 

 on the fungus diseases of insects, during the year 1878, together 

 with some more recent observations on the practical application of 

 parasitic fungi for the destruction of injurious species. The original 

 contribution is in the Russian language, " On the Diseases of the 

 Larvae of the Grain-beetle" (Odessa, 1878). Professor Metchnikoff 

 found that the Anisoplia austriaca larva, which lives in the ground, 

 is subject to several diseases, one of which he calls the " Green Mus- 

 cardine," being produced by a parasitic fungus Isaria destructor 

 (anisoplioi). The same fungus was also found to infest another 

 beetle, Cleonis punctiventris^ which is very injurious to beets. 

 In the month of August, when the disease had not yet disappeared, 

 about forty-live per cent, of the progeny of these latter beetles wa« 

 destroyed. Of the experiments made to infest the Anisojjlia larvse 

 with the spores of Isaria^ several were successful, but in some 

 cases the larvae remained healthy for a long time. The same experi- 



* ZoologisLer Auzeiger Xo. 47, pp. 44-47. (Riley, Am. Eut. Vol. Ill, p. 

 103, 1880). 



