REST PERIOD STUDIES WITH SEEDS 31 



with no other treatment (columns 4 and 2, Table 11) shows that the 

 ether apparently had no influence of any consequence on either the 

 time required for growth to begin, or total germination (lines 2 and 

 4, Table 13). 



Comparing dried seeds that were stratified and frozen with simi- 

 lar species of dried seeds untreated, it will be seen from columns 5 

 and 2 in Table 11, that fourteen of the former grew while only eleven 

 of the latter germinated. Twenty species of each were planted. The 

 stratified seeds, however, made a much earlier growth than the dried 

 ones, the average length of time required for growth to begin being 

 22.1 days, while the dried seeds on the average required 56.5 days. 

 Comparing the extent of germination in the two it is seen that 34.4 

 per cent of the stratified seeds germinated while only 17.5 per cent of 

 the dried seeds grew. (Table 13, lines 2 and 5). It is evident from 

 this that the custom of stratifying seeds after they have once been 

 allowed to dry out, is a very necessary practice. 



One lot of seeds of all species was etherized for twelve hours 

 after being dried, and then frozen while stratified. Comparing these 

 with similarly stratified seeds receiving no ether treatment (columns 

 6 and 5, Table 11), we learn that the ether treatment caused varying 

 results. In some cases the dormant period apparently was shortened, 

 while in other cases it was seemingly lengthened. In other words the 

 ether seemed to force certain species into an early growth, while it 

 hindered the growth in others. However, the percentage of germina- 

 tion was very markedly increased by the ether treatment, the average 

 increase being 8.1 per cent. The average time required for germination 

 to begin in the etherized seeds was 26.8 days, which was, on the aver- 

 age, 4.7 days longer than required for growth to begin in similarly 

 stratified and frozen seeds that received no ether. The ether treat- 

 ment seemed to cause germination to take place in three species that 

 did not germinate where similar seeds were stratified only, and in 

 four species the treatment apparently prevented germination, because 

 the same species without treatment grew. However, the ether increased 

 the total germination, as stated above, to the extent of 8.1 per cent. 

 (Table 13, lines 5 to 7). 



The final comparison is between seeds stratified and frozen and 

 then etherized for twenty-four hours, and similar stratified seeds re- 

 ceiving no ether treatments. (Columns 7 and 5, Table 11.) The ether 

 treatment increased the total germination by 9.4 per cent, but did not 

 shorten the rest period. 



It is interesting to compare all of the treatments as regards the 

 average length of time required for germination to take place. The 

 shortest time required for growth to begin (Table 13, line 5) was 



