432 Agricultural Experiment Station, Ithaca, N. Y. 



is perhaps an Isaria, the spores measuring 4.8 b}'^ 1.6 micron;;. It 

 is placed by Sorokin as belonging to a genus of Basidiomcetes 

 which he calls Metarrliiziumr 



The larvae iirst became rigid, and somewhat dnll in color. Soon 

 a white growth of mycelium appeared usually near the head or 

 between the sclerites. These small patches spread in a folinaceous 

 stroma, which is white and grows out into the surrounding soil for 

 a distance of 3 mm. or more. Sometimes it spreads very thin and 

 grows to a distance of 5 or 6 mm., clinging to the bits of vegetable 

 matter in the soil. This white stroma at length becomes colored a 

 dnll sage green by the production of conidia. The conidia are 

 from 5 to 7 microns in length and 3 microns in diameter. A dilu- 

 tion culture was made and germination became apparent in about 

 twenty-four hours. The conidia become swollen, and the proto- 

 plasm becomes condensed at both ends of the oblong conidium. 

 A slender germ tube is put out at one or both ends of the conidium. 

 After one day more branching commences and by two days more, 

 a few vacuoles appear. The branching growth increases steadily. 

 In about six days the vacuoles become oval and regularly placed 

 closed together throughout the entire length of the mycelium. The 

 colonies assume an irregular stellate form. A pure white growth of 

 branching threads appear above the surface and after about ten days 

 from the sowing conidia appear, borne in chains on heads of a pexnicil- 

 late type (Figs. 73, 74, and 75). These heads are borne on short pedicels 

 situated at short intervals on the main filaments. The production of 

 conidia is accoin panied by the appearance of a decided sage-green color. 



On potato, the growth shows itself after about six days, in finely 

 radiate colonies at the points of inoculation. A greenish center 

 soon appears and the white growth quickly spreads over the entire 

 surface of the potato forming a dense felt. This soon turns green 

 by the production of conidia. After a time, the conidia become 

 densely packed in a layer 1 mm. or more in thickness. The chains 

 of conidia still preserve their connection, and a columnar structure 

 is thus produced which extends through the layer perpendicular to 

 the surface of the potato. When a piece of this crust is broken, 

 the fracture follows the chains of conidia showing transverse stri- 

 ations. The mycelium is slightly 3'ellow at first, but later it becomes 

 tinged with green. 



.A number of specimens of Agriotcs mancus were rolled in con- 

 idia of Isaria anisojplioe var. ainericana and placed in pots of earth 



