DORMANCY IX THE SEEDS OF THE PERSIMMON 

 By H. L. Blomquist 



In the autumn of 1920 when the writer first came to Trinity Col- 

 lege, Dr. Bert Cunningham called his attention to the difficulty of 

 germinating seeds of persimmon {Diospyros virginiana). This fact 

 was observed while attempting to obtain root tips which in this plant 

 are rather favorable for the study of mitosis. When seeds were placed 

 under laboratory germinating conditions, occasionally a few would 

 germinate while the majority persisted in remaining dormant. From 

 these observations we concluded that here was another case of dorm- 

 ancy in seeds which has been shown by several investigators to be a 

 rather common phenomenon among wild plants. Since some of the 

 seeds would germinate occasionally, it seemed that it would be profit- 

 able to investigate the cause of the delay and the factors which bring 

 about germination in nature. 



In searching through the literature on the subject of dormancy in 

 seeds, no reference was found dealing with the persimmon. 



The seeds which were first used were gathered from the surface of 

 the ground since the season was too far advanced to obtain seeds from 

 the fruit. An attempt was made hoAvever to collect only those seeds 

 which had come from the preceding summer's fruit. A number of 

 these were put between moist filter paper in petri dishes and some in 

 soil. Under both conditions the same results were obtained; a few 

 seeds germinated while the majority, although plump and apparently 

 healthy, remained dormant. 



Simultaneously the morphology of the seed was studied. This 

 was found to be covered with a single taniferous coat of medium 

 thickness and a rather tough texture which adheres to the endosperm 

 except in the micropylar end Avhere it is underlain by another layer of 

 cells whicli caps the radicle of the embryo and to which the outer coat 

 does not adhere (fig. 1 ). Inside the testa is a thick horny endosperm 



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