Entomogenous Fungi. ' 431 



had attained a lengtli of from 5 to 9 mm. and a diameter of 1 mm. 

 sometimes expanded to 2 mm. On the sides of the sporophores are 

 borne shining yellow disks, smooth and either plane or irregularly 

 concave. These disks are composed of conidia held together by 

 some viscid substance (Fig. 95). On removing the Isaria-sporo- 

 phores, processes which are possibly the rudimentary stromata of 

 Cordycejps raelolontliae were seen. Several dilution cultures were 

 made, using the ordinary agar, but the fungus refused to grow, 

 further than to germinate. Potato agar was used, and the growth 

 progressed slowly. After three days the conidia appeared swollen, 

 and germination began by the production of one or two germ pro- 

 tubes. Vacuoles usually appear in the conidium and often at the 

 base of the thread. In four days the threads grew to quite an 

 extent, branching but little and showing no septa. The threads 

 sometimes show swellings at their base. At the end of six days 

 a few vacuoles and septa appeared. Many threads bear at their ends 

 round or oval bodies (Figs. 58 and 60), The protoplasm in these is 

 hyaline and homogeneous. Cylindrical conidia are borne in the 

 agar after the manner of most of the Isarias studied. In order to 

 get a pure culture on potato, a small piece of the agar containing 

 growing mycelium was transferred to a slab of sterilized potato 

 The growth on potato either sjDreads evenly over the surface or 

 grows in raised patches. The mycelium is dirty yellow in color 

 where it touches the glass of the tube. Conidia are borne in dense 

 patches on the surface of the felt. The production of conidia does 

 not always take place for this species in artificial cultures. 



ISAEIA ANlSOrLIAE (Metch.) Var. AMERICAI^A. n. v. 



During the fall of 1S93 about 1300 wireworms were procured 

 on which to experiment. They were chiefly larvae of Agrlotes 

 niancus. At Christmas time a fungus was seen to be growing on 

 them. It was provisionally identitied as Isaria anisopliae, since 

 the same fungus had previously been found by Mr. Slingerland in 

 his experiments and sent to Dr. Thaxter, who identified it pro- 

 visionally as Metar7'hizimn anisoj)liae.* The genus Metarrhizmmj 

 has since been included under Isaria. Thaxter f saj's Entoinoj)Ti- 

 thora anisopliae of Metchnikoif,| which attacks coleopterous larvae, 



*Bull, No. 33 Cornell Exp. Station, p. 211. 



tMem. Bost. Soc. Nat. History, Vol. IV., No. 6, 1888. 



t Zeitscber. d. K. Laudwirtb Gesell, of Neiuusslantl, Odessa, 1879, pj). 21to 50. 



