146 



THE PLANT WORLD 



further elongation occurred. As will be seen, about April 

 20th there was a falling off in the rate of elongation. The 

 reason may be in the fact that shortly after this time, the 

 later branches became evident and though their elongation 

 at first was quite slow, yet no doubt a good deal of energy 

 was utilized in their formation. 



The greatest elongation in any day was 9 '/. in. ; the 

 greatest daily average for a week was for the week ending 

 April 1 6th, and was 7 5-14 in. The mean for the total 

 period observed wa sapproximately ^ in. per day. 



The stalk of the other plant mentioned was marked off 

 into zones to determine the region of elongation. These 

 zones were 6 in. broad, starting at the base, the final one at 

 the apex being only 4 in. The following table shows the 

 relative growth, the numbers being from the apex down- 

 wards : 



It appears from this that the region of most active elonga- 

 tion is that lying a short distance, perhaps about 12 in. be- 

 low the apex. 



