1913-14.] BOTANICAL SOCIETY OF EDINBURGH 205 



in all the others, while the growing region, though less than 

 I. and II.. is greater than III. 



In the root the two curves vary together, also at the 

 beginning, but the growth region curve flattens out later. 

 In comparison with the others the two curves show a 

 diminution in height, though the growth curve is about 

 the same as II. These curves show a slight increase at 

 the beginning followed by a decrease, probably due to the 

 after effect of the normal conditions later overcome by the 

 retarding influences of the light. 



There is a correlation between the growing region of 

 root and shoot, the latter increasing as the former is on the 

 decrease, as is the case of the growth in length. 



Conclusions. 



(For roots of Vicia Faba.) 



1. Daily variations, irregular in character, occur in the 

 lengths of the growing regions of root and shoot under 

 ordinary conditions. 



2. The growing region in the shoot varies very little in 

 Intermittent conditions from the Normal. 



It varies most in the Dark, when it decreases, even though 

 the growth in length increases. 



In the Light the growing region decreases, but to a less 

 extent than in the Dark, while the growth also decrea- 9 



3. The growing region of the shoot varies very closely 

 with the increase of growth from day to day. and the 

 maxima of both correspond under all the condition-. 



4. The growing region in the root varies under the 

 conditions II.. III., and IV.. and is evidently more easily 

 influenced than that of the shoot. 



E.'j. In the Normal the growing region slowly increases, 



then decreases. 

 In the Intermittent the growing region decreases, 



then remains uniform. 

 In the Dark the growing region decreases, then 



remains uniform. 

 In the Light the growing region increases for a short 



time, then decreases and remains uniform. 



5. The o-rowino- reoion in the root varies with the growth 



