14 



are better, a feature which will be discussed later. The experiments, 

 nevertheless, are instructive as showing how pruning a few of the 

 lower leaves, which constitute secondary organs, affects the growth 

 of the stem and fruit. It should be borne in mind, however, that 

 besides the removal of the lower leaves, usually a half dozen or more 

 from each plant, the plants were grown to a double stem in all cases 

 except those given in Table I. This necessitated, where the experi- 

 ments were prolonged, nipping out all the branches and auxiliary 

 shoots as fast as they appeared, in both the check and pruned plants. 

 Moreover, the plants were all grown in lo inch pots and this method 

 of culture has a tendency to check profuse development. There is 

 some difference shown in 'I'able I in the growth of fruit and leaders, 

 as the result of cutting the lower leaves. It might be expected that 

 the fruit would respond less under such treatment than the stems. 

 The experiments shown in the other tables were more or less pro- 

 longed, as the result of which the differences in the increased size 

 and weight of fruit were smaller. This is what in general might be 

 expected, inasmuch as the longer the period elapsing between stimu- 

 lation (cutting) and the time of noting the response, the less striking 

 would be the effect. This is especially true where the nature of 

 stimulation is of a character which is not destined to produce impor- 

 tant modifications in the development of the plant. \Miere the stim- 

 ulation is more pronounced, or repeatedly applied, more important 

 differences will be seen between the development of the pruned and 

 unpruned plants. Moreover, where a single application of a stimulus 

 of an insignificant character is applied, such, for example, as occurred 

 in removing only a few of the lower leaves of a tomato plant, it would 

 be expected that the plant would soon recover from the loss of 

 foliage or gain a sufficient amount to counter-balance the loss and 

 functionate normally. In this case the removing of a few leaves from 

 the plant would not affect its normal development to any great extent. 

 On this supposition, one would expect to find little or no effect of 

 pruning two or three months afterwards. That such is the case is 

 readily seen by the results shown by the various experiments. VMien 

 the experiment lasted one month the increase in the size of fruit was 

 2 1 per cent, when of two months duration it was lo per cent; when 

 it lasted three months it was 6 per cent. 



