910 The American Naturalist. [October, 
VIII.—Gerrmination or RIPE, UNRIPE, AND OLD SEED OF 
RED CLOVER. 
Experiment conducted by Nobbe. 
Degree of ripeness, Per cent of total ages Total germination. 
Soon after | 4 yearsafter Soon after | 4 years after 
gathering. gathering. | gathering. | gathering. 
pecans! mee 
Immature seed..........+++ 63 0 48 6 
90 | 24 88 58 
grown on good and on poor soil are compared. It has been 
noticed by tomato growers that more seed is obtained on poor 
than on rich soil,” which accords with the record for imma- 
ture strains.“ The difference in fertility of soil need not be 
especially marked to secure the effect, if other conditions are 
reasonably uniform, even good soil compared with yet richer 
soil produces the characteristic results. In some experiments 
on wheat made by Latta,” the yield on good wheat land was 
one pound of straw to .55 of a pound of grain, but the same 
land richly fertilized gave one pound of straw to only .48 of a 
pound of grain (see table IX); that is, the poorer soil brought 
about a greater development of the reproductive parts of the 
plants, as compared with the vegetative parts, than did the 
richer soil, without regard to the mode of fertilization. This 
phase of the subject might be extended to great length and 
many statistics given, but it will suffice for illustration to ap- 
peal to common observation of the remarkable size of the 
flowers and seed pods of depauperate weeds and other plants, 
and on the other hand, the tendency of plants in rich soil to 
produce foliage shoots rather than fruit. 
It has been recognized by zoologists* that “ checks to nutri- 
* Allen, Amer. Gard., xi (1890), p. 358. 
“ Goff, Rep. Wis. Exper. Sta., viii (1891), p. 157. 
“ Bull. Ind. Exper. Sta., No. 41 (1892), p. 94. 
“Geddes and Thompson, Evolution of sex, p. 218, 
