FALL SOWING 217 
lay down a definite rule covering the time of fall 
sowing. The dry-farmers in such places usually 
sow at any convenient time in the hope that an early 
rain will start the process of germination and growth. 
In other cases planting is delayed until the arrival 
of the first fall rain. This is an uncertain and usually 
unsatisfactory practice, since it often happens that 
the sowing is delayed until too late in the fall for the 
best: results. 
In districts of dry late summer and fall, the eee 
est danger in depending upon the fall rains for ger- 
mination lies in the fact that the precipitation is 
often so small that it initiates germination without 
being sufficient to complete it. This means that 
when the seed is well started in germination, the 
moisture gives out. When another slight rain comes 
a little later, germination is again started and pos- 
sibly again stopped. In some seasons this may occur 
several times, to the permanent injury of the crop. 
Dry-farmers try to provide against this danger by 
using an unusually large amount of seed, assuming 
that a certain amount will fail to come up because 
of the repeated partial germinations. A number of 
investigators have demonstrated that a seed may 
start to germinate, then be dried, and again be started 
to germinate several times in succession without 
wholly destroying the vitality of the seed. Nowoc- 
zek has conducted a number of experiments on this 
subject, with the following results: — 
