16 BOTANICAL GAZETTE [JULY 
stage, the results show that there was a material lessening of the power 
to remove phosphate, probably due to the fact that the process of the 
phosphate absorption had not fully replaced the opposite function 
existing during germination and early growth. 
The potassium absorption is also different from that in the later 
periods, although this is not so striking in the diagrams as in the case 
P05 
j 
Vj 
f\. 
f 
A 
me + Par annrst 
\ 
«30 NH> 
Fic. 7.—Showing the ratio of the original, the final, and the ratio of the loss of 
P,O,;, NH;, and K,O from the culture solution of the second period. 
of the phosphate. The average ratio of the removed material during 
these first three periods for all the cultures is 19 for phosphate, 39 for 
nitrate, and 42 for potassium; whereas the average for the five succeed- 
ing periods is 21 for phosphate, 44 for nitrate, and 35 for potash, thus 
showing that there is a tendency for a relatively greater potash and — 
a relatively less phosphate absorption to take place during the earlier 
periods. So far as the influence of these fertilizer elements on growth 
is concerned, however, it is to be noticed that the nitrate has the 
