170 



Hydration and Growth. 



accession of material is very much greater. Then, in fmi;her develop- 

 ment, the average increment to the diameter was smaller, yet the actual 

 accession of material was greater (see September 4). Following this, 

 the rate falling from 0.8 to 0.3 mm. daily, the accession decreases less 

 than half. (See figs. 51 and 52.) 



Table 123. Table 124. 



Attention was now directed to temperature effects as measured in 

 this manner. Two plants were placed in chambers subjected to equiv- 

 alent diffuse illumination and humidity. The fruits similar to those 



-I t- 



Fio. 51. — Diagram illustrating the course 

 of growth of a tomato during the six 

 weeks of its development. The broken 

 line is plotted from the average daily 

 rate of growth during each week, and 

 the solid line from the calculated in- 

 creases in volume. 



Fia. 52. — Similar to fig. 51, but begin- 

 ning at an earlier stage. The average 

 daily rate is seen to form a graph which 

 presents notable differences from the 

 one plotted from variations in volume. 



measured in one showed thermometer readings of 19° to 21° C. and 

 in the other 29° to 31° C. The daily rates of axial increase were as 

 shown in table 124 for the weeks beginning on the given dates. 



The conditions under which both plants were grown were unfavor- 

 able to development, but it is to be noted that the rates of increase 



