PROPAGATION BY MEANS OF SEEDS AND SPORES 21 



conditions of moisture and temperature can be maintained. 

 Seeds sown on a moist surface and covered with a glass 

 present an interesting study. They may have difficulty in 

 getting a foothold, and they present peculiar reactions to 

 light. 



It is well known, on the other hand, that some seeds will 

 not germinate, or will at least appear unevenly, if subjected 

 to sunlight. At least some of the delphiniums, papavers and 

 adonises germinate very imperfectly, if at all, in direct light. 

 It is always advisable to keep germinating seeds in shade or 

 partial darkness, especially as there is nothing to be gained by 

 exposing them. Of course, the soil itself is sufficient protection 

 if the seeds are covered. 



Regermination 



It is a common statement that seeds can never revive if 

 allowed to become thoroughly dry after they have begun to 

 sprout. This is an error. Wheat, oats, buckwheat, maize, 

 pea, onion, radish and other seeds have been tested in this 

 regard, and they are found to regerminate readily, even if 

 allowed to become thoroughly dry and brittle after sprout- 

 ing is well progressed. They will even regerminate several 

 times. 



Wheat, peas and other seeds have been carried through as 

 many as seven germinations after the radicle had grown a half 

 inch or more and the seeds had been sufficiently dried in each 

 trial to render them fit for grinding. 



Delayed germination , 



We noted in Chapter I that most seeds have a natural period 

 of dormancy. This period may be considerably shortened or 

 lengthened in many cases by the treatment to which the seeds 

 are subjected. 



