THE AMERICAN BOTANIST 67 



have never seen a four-parted Trillium erectum, T. undulatum 

 or T. ccrnuum. The latter species is rare here but T. undulatum 

 is found in upland woods and about mountain ponds. — Stewart 

 H. Burnham, Hudson Falls, N. Y. 



Effects of Pollination. — The flower exists for the 

 purpose of producing egg's and sperms and for facilitating the 

 union of these bodies. The beauty and fragrance so attractive 

 to us are merely incidental. The first of the processes with 

 which the flower is concerned is pollination. With the phen- 

 omena attending this we are all more or less familiar, but many 

 fail to realize the extent of the changes which result from 

 the depositing of the pollen on the stigma of the waiting 

 flower. When this occurs, the pollen tube begins to grow 

 down through the carpel until it reaches the ovule where its 

 contents, fusing with the contents of the ovule, fertilizes the 

 egg, causing the embryo plant to develop. The stimulus of this 

 act usually reaches much farther for the ovary begins to swell 

 to form the new fruit and not infrequently the receptacle en- 

 larges as well, as in the case of the apple and strawberry, 

 where this becomes part of the fruit. Plants, however, vary 

 considerably as to the extent to which pollination or fertiliza- 

 tion affects these processes. Every season uncounted millions 

 of flowers open but, failing to be properly pollinated, are cut 

 off by the parent plant and fall to ground unnoticed. There 

 are, to be sure, some plants, such as the navel orange, which 

 may produce fruits without pollination, but this is unusual. 

 There are other plants in which pollination alone is sufficient 

 to cause fruits to develop, though of course without seeds, but 

 in the great majority, fertilization is necessary, and in a few, 

 such as the pumpkin and its allies, the stimulus of the growing 

 seeds is necessary to continue the development of the fruit. 

 This explains the failure of many pumpkins to go on to 

 maturity after enlarging to possibly half the natural size. In 

 the apple, the flavor appears to be largely dependent upon the 



