708 Miller.—A Physiological Study of the 
By obtaining approximately the same results on seedlings that have 
been grown at different times, it seems certain that the results obtained at 
any stage are a true representation of the normal conditions at that stage. 
In Table II the averages of the analytical results for each stage of the 
seedlings are shown. 
The results obtained in experiments with germinating seeds in most 
cases have been expressed as per cents of the dry material analysed. Results 
of this character fail to give a complete account of the changes taking place, 
and in fact may give one an entirely erroneous conception of the processes 
at work. The original weight of a certain number of seeds after a period 
of germination may have increased or decreased to a considerable degree. 
In such a case it is readily seen that the expression of the results in per 
cent, only throws little light upon the actual depletion or increase of con¬ 
stituents. Take for example the amount of the ether extract of the 
cotyledons of the sunflower as expressed in Table I. In the cotyledons of 
the resting seed the amount of ether extract as expressed in per cent, of the 
dry material is 55 % to 56 %, while in the cotyledons of Stage I, where the 
hypocotyls have reached a length of 2*5 to 3*5 cm., the per cent, of the oil 
on the weight of the dry material is practically the same as that in the 
cotyledons of the resting seeds. The amount of oil has apparently not 
decreased in the cotyledons during the three days leading up to Stage I. 
But when one finds that the total weight of the cotyledons has during that 
time decreased one-fifth of their original weight, it is readily seen that the 
amount of oil really present in the cotyledons at the stage mentioned is 
much less than that in the cotyledons of the resting seed. 
Evidently the only way in which one can obtain a clear idea of the 
increase or decrease of the constituents in seeds during germination, or of 
the changes that are taking place at any one stage, is to find the actual 
amount of each constituent in a certain definite number of seedlings at the 
stage examined. One hundred seeds or seedlings were used as a basis in 
this work. The weight in grams of one hundred cotyledons at any stage 
examined was multiplied by the amount of the constituent in per cent, of 
dry material. This thus gives the amount of that constituent in grams in 
the cotyledons for that stage. The amount of the different constituents 
in one hundred hypocotyls at any stage was obtained in the same manner. 
To find the actual increase or decrease in weight of a lot of seedlings 
relative to the seeds from which they originated is a difficult task. The 
two main difficulties encountered are due to the fact that the rate of ger¬ 
mination in seeds varies so much, and that in every case some seeds either 
fail to germinate, or the young hypocotyl is unable to make its exit from 
the seed-coats. For that reason the attempts at the beginning of the work 
of planting one hundred weighed seeds, and of digging up the seedlings 
when they should have reached the proper stage, were a failure. 
