52 BOTANICAL GAZETTE [july 



tion, and all those seeds that had suffered injury, however slight, 

 in removing them from the carpels invariably decayed. 



To remove the possibility of coat effects, we next removed the 

 testas and treated the embryos as above; when thus treated an 

 occasional hypocotyl grew, varying from none to 3 or 4 per cent. 

 Crocker (2), who previously employed this method, indicated a 

 higher percentage of growth. The behavior of the embryos under 



him 



remarkable 



hypocotyl. In the light the cotyledons soon turn a dark green and 

 enlarge often to several times their original size. The hypocotyl 

 does not elongate, but remains short and blunt. In case of ger- 

 mination after complete after-ripening, the hypocotyl takes prece- 

 dence and elongates rapidly, while the cotyledons increase in size 

 much more slowlv and never reach the size attained in case the 



hyp 



the 



contained 



We next carried on experiments to determine the effect of low 

 temperatures in bringing about after-ripening and germination. 

 The first set of experiments was carried on in an ordinary ice chest 

 so arranged as to admit light to some of the cultures. With this 

 we were able to obtain a temperature of 5°-6° C. 



In all cases the seeds treated were placed on wet cotton in Petri 



■ —a 



dishes 



temperatures 



These were 



treated in test tubes with cotton plugs. Table I gives the results 

 of the first set of experiments. 



In these cultures the number of seeds germinated compared with 

 the total number treated may seem rather low, varying as they 

 do from 50 to 80 per cent. This is not due to the seeds failing 

 to germinate when removed from the cold, but almost entirely 

 to loss during the process of after-ripening. It is quite difficult 



remove 



While 



removed 



knife, yet many suffered more 



ced upon the ice. The 



broken 



