Observations on Growth of Fungus Parasitic on Locusts. 73 



been some phases of the reproductive process which I may have 

 overlooked, either from inaccuracy of observation or inexperience in 

 working microscopically with fungi. But I may here state that I 

 made repeated experiments with the fungi from many separate culti- 

 vations, so that I over and over again clearly made out and verified 

 the phenomena above described by numerous separate observations 

 on many different occasions. 



Suitability of Media for Growth of the Fungus. 



As I have said, the primary cultivation experiments were made on 

 glycerine-agar peptone, and that medium was always found very 

 suitable ; but the fungus grew well on many other media, such as 

 gelatine peptone, sugar agar, a solid medium made with crushed 

 locusts : in fact, on all nitrogenous solid media it grew well. On 

 bread paste and on potato it grew slowly at first, but after the lapse 

 of a fortnight the growth suddenly became fairly luxuriant. I have 

 stated above the cause to which I attribute this phenomenon. In 

 nitrogenous fluid media, such as beef bouillon, a bouillon made from 

 dead locusts, &c, it grew most vigorously; gradually filling the 

 upper part of the tube with a fine flocculent growth, which close to 

 the surface became a dense felted network. Only the asexual forms 

 of growth took place in the fluid, but these were produced with 

 the greatest exuberance, conidia being thrown off and mycelium 

 being formed in all directions. When the growth came to the 

 surface aerial filaments were formed with the production of spores 

 in the way above described. The more vigorous growth close to the 

 surface supports what I stated above with regard to the growth in 

 solid media that the appearance of air is necessary for active growth. 



In media made from non-nitrogenous substance, such as starch 

 and sugar, the growth was not nearly so abundant, and soon ceased. 

 In comparing tubes of bouillon and tubes of strong starch and sugar 

 solution sown with fungus spores on the same day, after a week's 

 growth this difference was very remarkable : in the nitrogenous tube 

 the growth being vigorous and abundant, in the non-nitrogenous 

 it being feeble and scanty. Besides, on microscopic examination, 

 the mycelium in the carbohydrate solution was very pale, extremely 

 vacuolated, and the granularity of the protoplasm was absent, and 

 also in the older mycelium there was marked fatty degeneration of 

 the protoplasm, large yellow globules of oil being abundant in the 

 cells, the protoplasm of which was collapsed. It would thus appear 

 that the fungus is one which needs nitrogenous matter for its healthy 

 growth. From the foregoing considerations, the ease with which 

 the fungus grows on various media, at ordinary room temperature, 



