ROSE— DEL A YED GERMINATION 



420 



It is plain that treatment with the machine increased germi- 

 nation considerably in the case not only of legumes, but also of 

 snapdragon, Delphinium, sweet marjoram, Ipomoea, okra, and 



lettuce. 



TABLE I 



Germination of seed treated with machine 



Kind of seed 



Germination 



Alfalfa 



Alfalfa 



Bossiaea hetcrophylla 



Bossiaea scolopendria 



Clianthus Dampieri 



White clover 



Delphinium chinense 



Dilliwynia ericifolia 



Gleditschia 



Ipomoea (average of 3 spp.) 



Lathyrus (average of 3 vars.) 



Lettuce (average of 1 1 vars.) 



Sweet marjoram 



Mustard (average of 2 vars.) 



Okra 



Perennial peas (average of 2 vars.) . 

 Sweet peas (average of 5 vars.) 



I'latylobium trilobatum 



Snapdragon 



Vetch 



Average 



Increase due to treatment .... 



It is not strictly correct, however, to call lettuce seeds hard- 

 coated. That their germination is improved by treatment with the 

 machine shows delay to be due to coat restrictions. The coat 

 restrictions are removed also by soaking in water for 24 hours, 

 hence it is likely that delay is caused by a reduction in rate of 

 water absorption rather than by lack of oxygen. Whatever be 

 the character of the seed coat, or coats, which interferes with 

 germination, it disappears as the seed grows older. These points 

 are well illustrated by table II. The data here presented support 

 the statement made by various seedsmen, that two or three-year- 

 old lettuce seed gives better germination than fresh. How this 

 condition comes about is not known, but it probably depends on 



