STAMENS. 463 



Uro-Skinneri have been found reduced to filamentous 

 processes. 



Abortion of the stamens. Atrophy of one or more sta- 

 mens is of very common occurrence, as a general rule, 

 in many genera of plants, e.g. Scrophularia, Er odium, 

 many Bestiacece, &c. &c. As a strictly teratological 

 condition atrophy of the stamens is more rare than 

 complete suppression. It has been noticed in Arabis 

 alpina, Cerastiwm glomeratum, G. tetrandnirriy Rhamnus 

 catharticiis. Anemone, Hepatica, &c. It happens fre- 

 quently among Orchids both wild and cultivated. In 

 the HymenocaUis flowers described by the elder Morren, 

 four out of five stamens were atrophied. In other 

 flowers, otherwise perfectly formed, one abortive sta- 

 men was found bearing a spherical indehiscent anther. 

 All these atrophied anthers of HymenocaUis were found 

 to contain pollen, differing at first sight but little from 

 what is usual, but presenting this important peculiarity, 

 that while the normal pollen does not burst until it 

 comes into contact with the stigma, in the abnormal 

 flowers the outer coat of the pollen-grains split while still 

 within the anther, from which latter, indeed, they could 

 not escape, owing to the indehiscent nature of the latter. 

 Again, the pollen-tube of the abnormal grains cracked, 

 in its turn, on mere exposure to the air, and liberated 

 the fovilla, so that the pollen of these atrophied anthers 

 was necessarily impotent, because it opened before it 

 could be applied to the stigma, even had that been 

 rendered possible by the opening of the anther. 



An abortive condition of the stamens and of the 

 pollen, is of very common occurrence among hybridised 

 plants. Gaertner and other writers have spoken of 

 this defective condition as contabescence.* It forms 

 one reason for the sterility so fi'equently observed in 

 the case of true hybrids. In some hybrid passion- 

 flowers, while all other parts of the flower were appa- 

 rently perfect, even to the ovules, the stamens were 

 ' See Darwin, ' Yariation of Domest. Anim. and Plants,' ii, 165. 



