variations in rrowth-rate are here considered as due to :' 

 ternal variations, with tine, and to he studied 



reference to the duration factors. As. to r'r.ternal condi- 

 tions, tv.ro cultures may differ (l) wi1 "espect to the ini- 

 tial status of the?- ditions (nature of the inoculs ting 

 material), and (2) respect t< rate and direction 

 of internal changes ?oir- - •- the development of the 

 mycelial mat. Since the initial internal conditions 0" 

 one funpus ;vas the same, there enter into this s~ " - four 

 sets of initial internal conditions, (t] itial internal 

 conditions heing here understood to ions at 



.e of inoculation). T ;se four correspond to the four f 



■ specias employed- 



■following scheme may serve to show the sorts of 

 tai enter into the interpretative comparisons that 

 need to " .\e. 



[Sche 



the same ;-s 



I. nal cond s (nature of fungus) 



1. Initial conditions, alike for all cultures. 



2. Direction and nate of internal variation during 



culture period, may he different from c - " • 

 ture to culture. This variation always to 

 he stated as withir the limits x 



(1) the initial ' nal conditions ai 



(2) the external conditions. 



II. Eternal conditions (environment) • 



1. Initial environmental conditions excepting te - 



perature considered alike for all cultures. 



2. Initial temperature conditions differ?:-.-", from 



culture to culture. 



18 



