not th« s-i \e as that for any 24-h< ur period* It fol- p 



lews from this that the growth- temperature graph for ea<:h or- 

 ganise altera its shape as we proceed from one observation 

 period to another in the continuous series, as is clear fro- 

 superficial inspection of the figures. T ', s prorrress: 



change in the form of the growth-temperature graph of course 

 represents a corresponding progressive change in the growth- 

 temperature relation cf the fungus, as time elapses after in- 

 oculation. Since the external conditions of these experiments 

 are considered as not altering with, time, this apparently grad- 

 ual change in the growth- tempera tu re relation must be evident 

 of internal changes occurring in the organism. Just what 

 these changes may be is not a mat* at can he considered as 



yet, but it is possible to study them as they affect the growth- 

 temperature relation j the progressive alteration in the form 

 of the graph representing this relation is itself a cleajf in- 

 dication of certain features of the effectiveness of the in- 

 ternal alterations within the organism. 



A1J the graphs agree in showing a mry small value for 

 the growth rate with the lowest maintained temperatures studied* 

 In all cases the mj temperature (below which no growth oc- 



curred under the conditions of these experiments) was apparent- 



o 

 ly below C 



With maintained temperature progressively higher t 



the minimum the rate values are progressively larger, till the 



maximum rate represented by the graph is reached. With still 



higher maintained temperature the rate is progressively lower, 



so that the optimal temperature represents, the max J 



graphs, considered as a curve. This max growth rate dif- 



* 



