observation period ard the time location of this observe 



in relation to the beginning of the experiment considered to 



y& zero time. 



Fince the experimental cultures are all regarded as 

 alike at the time of inoculation, the duration conditions may 

 he regarded as beginning to operate from the beginning of this 

 culture period, the time of inoculation being considered zero 

 time. If either the length cf the culture period or the tire 

 between observations for any culture is different from that 

 for another, this fact is of course quantitatively shown >y 

 the records of times of inoculation and times of observatic 

 and measurement, T srefore differences in these conditions 

 are taken into account in the interpretation of growth differ- 

 ences in terms of length cf observation periods and also in 



relation to the time location of this observation period to 

 t v e time of inoculate" ^-erarded here as zero time. 



"From the preceding discussion it will he observed 

 (l) that the research at hand was so rlar-ed as to involve 

 the actual or assumed maintenance, during the respective cul- 

 ture periods cf all the groups of effective conditions ex- 

 cepting internal ones, and (2) that the only conditions con- 

 sidered as effectively different from culture to culture are 



(1) nature cf the fungus used (initial internal conditions), 



(2) rate and direction of internal variation, v ' + '-e or- 

 ganism, and (3) maintained temperature. 



r any given culture all the effective envi ~- r ' sntal 

 conditions are assumed to remain the same throughou 4 " tl 3 cul- 

 ture period. For this given enrironmental complex, the 



