THE AMERICAN BOTANIST. 35 



stamens have them, open forward, that is, inward towards 

 the center of the flower. 



Cutting off one of the stamens for closer inspection 

 under a magnifier, I was interested to observe that, caused 

 by the warmth or dryness of the air in the room, in a 

 short time the anther cells began to dehisce. First one lid 

 sloAvh' raised itself and began to swing forward on its 

 hinge, then the other, until in a few minutes both lids had 

 opened widel}' and stood back to back, each having com- 

 pleted a half-circle of revolution. There would have been 

 nothing particularly noteworthy about this had it not 

 been for the fact that it was not the lid alone that moved, 

 but that the pollen contained in each cell came out on the 

 lid of the cell, leaving the cell itself, perfectly empty. 



This was true with all the anthers I examined, both 

 those which had opened naturally and those which I 

 caused to open. Sometimes both lids would rise together 

 and swing rythmically forward, sometimes one would be 

 more or less in advance of the other. This is doubtless a 

 device for aiding in the pollination of the flowers. The 

 pollen is thus moved forwards and placed in a very ex- 

 posed position, so that s.r\y insect which comes to the 

 blossom can hardly help getting some of it on its legs or 

 proboscis and thus, if it visits another flower, effect the 

 cross-tertilization that the plant desires. 

 Garrettsvilk, Ohio. 



THh WANDERING MILKWEED. 



BY E. S. GILBERT. 

 TT is a midsummer morning just at sunrise and the south- 

 ^ ern side of this thick grove of bass wood, ash, maple, 

 etc. lies in deep shadow, wet with dew. Between the 

 beaten path and the tall trees the ground is overgrov^m 

 with masses of strong plants two feet or more high and 

 the air is filled with a pleasant smell which might be called 

 a fragrance though close at hand it is less agreeable and 

 has a suggestion of a potent bitterness. It is the Indian 

 physic or wandering milkweed {Apocynum androsaemifo- 



