204: THE PLANT WORLD. 



twig, both ends being fastened to the cap. A week later only 

 four caps remained, the others ha\'ing been pulled off accident- 

 ally. These four remaining caj)s were removed and the flowers 

 taken from the tree. The calyx was literally filled with pollen 

 from the opened anthers, but tlie pistil remained a mere rudi- 

 ment, somewhat shrivelled and no larger than before. In each 

 of the four flowers the calyx was uninjured and the taking (^nt 

 of adjoining flowers probably had in no way interfered with the 

 process of self-fertilization, if it had otherwise been possible. 

 From til is evidence it seems probable that self-fertilization does 

 not occur. 



A furtlier point investigated was as to whether pistillate 

 flowers are ever self-fertilized. It is well known that all pistil- 

 late flowers contain a few, more or less rudimentary, stamens. 

 Close examination shows a few of these stamens to produce pol- 

 len, but in every case thev are so tardv tliat bv the time tlie 

 anthers are ready to scatter their pollen, the air is already filled 

 with the pollen from staminate flowers, and the ovaries are 

 already quite distended. 



An important fact in cross-fertilization was also observed, 

 namely, that all trees produce their stamimite flowers several 

 days earlier than their pistillate flowers. As the time of flower- 

 ing varies with different trees, one tree mav often have shed its 

 pollen before its pistillate flowers are ready to be fertilized and 

 hence a neighboring tree must be depended upon, Staminate 

 flowers were found from March 28th to April 15th, and pistillate 

 flowers from April 5th to April 18th. 



In passing, an observation in regard to the fruits may be 

 recorded. Sargent (Trees of ISF. A., page 638) states that the 

 fruit "ripens in April or May before the appearance of tlie 

 leaves." This statement certainly can not be verified in this 

 locality, nor have I ever seen trees farther east that would bear 

 out this statement. The first fruit ri])eus in from forty to forty- 

 five days after flowering, or about thirty-five days after the leaves 

 begin to appear. The first pistillate flowers were foimd on April 



