i8o BOTANICAL GAZETTE [march 



grown mycelia were not suitable for the germination of spores, 

 the spores used in the first cultures were germinated before inocu- 

 lation. This method was extremely unsatisfactory, because the 

 germinating spores could not be evenly distributed in the culture 

 liquid. Moreover, it was found that spores germinated well in all the 

 media used. Attemnts to innmlatp the fla=;V'; bv 



means 



be 



even distribution of the dry spores. The method finally adopted, 

 which proved entirely satisfactory, was as follows: A stock-culture 



beans 



growing; the liquid was then 



poured on a screen of fine-meshed muslin in a funnel 

 into a sterilized flask. This 



been 



gav 



ery 



into the flask. For inoculation three 



dropped 



This gave an abundance of spores, perhaps some thousands, which 

 were uniformly distributed in the culture fluid. 



The yield of dry material produced was used as an indicator of the 

 effect of the food given. The yield was determined by adding lo" of 

 a lo per cent, solution of chemically pure hydrochloric acid to the 

 culture to kQl the growth and dissolve any precipitates that had been 

 formed. After this the culture was filtered on a hard filter paper, 

 from which the fungous material was washed into a tared Gooche 

 crucible, and dried at 100-110° C. The variation in the temperature 

 at which the yields were dried was not preventable, since no regu- 

 lated dr}^mg oven was avaflable. AU the yields of each series were 

 dried at the same tune. howpv*^r «;n ilmt tTi^^r w^^r^ QiibiVrfed to the 



same conditions in drying. The 

 therefore comparable with each nt1 



TABLES AND EXPLA?rATIONS 



In the following tables are given the results of the cultures 



necessary 



o 



In the course of the 



work many hundreds of cultures were made before finaUy satisfactory 

 details of manipulation were worked out, and for the purpose of deter- 

 nunmg the concentrations of the various substances that permitted 



