(171) 
studied by various workers the correlations of position are 
but little known. The main value of the experiments seems 
therefore to lie in the fact that they point to an interesting 
field in the study of position correlations and the relation be- 
tween position and size. 
The length reactions, as observed in the present case, are 
on the whole unexpected. The experiments on the enlarge- 
ment of the stipules in many leaves after the removal of the 
leaf-blade,* the replacement, in Streplocarpus, of the large 
leaf-like cotyledon by the smaller one after removal of the 
former,t and many other cases would lead us to expect an 
enlargement of the remaining leaflets after the removal of 
one of them. Instead of this we get a very constant and al- 
most uniform decrease in all three species. This corresponds 
with the results obtained by Knyt in willow-cuttings (Salix 
and Ampelopsis) where the continued removal of the shoots 
retards the growth of the roots and vice versa. F. Hering § 
found a similar retardation in the growth of one member of 
a seedling when the other was imbedded in gypsum. Ex- 
periments by Kny and Hering in which either the root or 
the shoot of a seedling was removed, however, showed no 
effect upon the growth of the other part, except that Hering 
found a retardation for a short period after the operation. 
The brief decline Townsend || has pointed out is probably 
due to the effect of the injury stimulus and Kny has further 
suggested that the later apparent independence of growth 
may be due to the accelerating influence of the regenerating 
shoot on the root or of the root on the shoot. 
The reactions in the present experiments were entirely 
free from any factor due to the stimulus of a regenerating 
*Goebel, K. Organographie der Pflanzen, 180. 1898. 
{ Hering, F. (Uber pes cabernet aaa in eos mechanischer Hem- 
mung des Wachsens.) Jahrb 142. 1896. 
tKny, lL. On eoreinuiee: in ie growth of roots and shoots. Ann. Bot, 
B: 265. 1894; Second paper. Aun, Bot. 15: 613. Igo1. 
2 Hering, 7. c. 139. 
|| Townsend, C.O. The correlation of growth under the influence of in- 
juries. Ann.Bot. 12: 509. 1897. 
