442 BOTANICAL GAZETTE [june 



attention must be given than formerly to pathological phenomena. 

 Observations on this point should be given along with other data 

 from the experiment. 



3. The causes of delayed germination in asters, certain hardy 

 perennials, labiates, ornamental grasses, cucurbits, conifers, frosted 

 oats, Betula, and Berbcris. 



4. The value of hard seeds of legumes when planted in the soil. 



5. The relation of any or all of the causes of delayed germi- 

 nation to the vigor of the plants produced. It is not enough that 

 a given lot of seeds shall be free from impurities; it is not even 

 enough that it shall give a high germination percentage. It must, 

 above all, give rise to vigorous productive plants, when planted in 

 field conditions. Consequently, any knowledge which will teach 

 us how to grow such seeds and how to know poor seeds is of the 

 greatest practical importance. 



Summary 



1. Hard-coated seeds of legumes, and seeds of Delphinium, 

 I pomoca, lettuce, mustard, okra, sweet marjoram, and snapdragon 

 can be forced to more rapid germination by being blown against 

 needle points. 



2. For two varieties of lettuce it is shown that the seed improves 

 in viability as it grows older, up to the end of at least the fourth 

 year. This improvement is probably due to increased perme- 

 ability of the inner seed coat to water. 



3. Cold storage in wet sand increased the germination seeds of 

 Pinus Strobus by 32 per cent, of Cupressus macrocarpa by 31 per 

 cent. Delayed germination of conifer seeds, more especially those 

 of Pinus Strobus and P. austriaca, seems to be due to lack of water 

 intake, and not to an alkaline or neutral reaction of the embryo. 

 This statement is supported by the fact that seeds injected with 

 distilled water gave better germination than those merely soaked 

 in water or in weak acid at the temperature of melting ice. Any 

 kind of soaking or injection gave 13-38 per cent better germination 

 than was obtained with the controls. 



4. Certain samples of frosted oats improve in germinating 

 power as they grow older, others deteriorate. 



