STAMENS. 4.63 
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, Hrodiwn, 
many festiacew, &c. &e. As a strictly teratological 
condition atrophy of the stamens is more rare than 
complete suppression. It has been noticed in Arabis 
alpina, Cerastiwum glomeratum, C. tetrandrum, Rhamnus 
catharticus, Anemone, Hepatica, &e. It happens. fre- 
quently among Orchids both wild and cultivated. In 
the Hymenocallis 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 Hymenocallis 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 stili 
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 frequently 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 
1 See Darwin, ‘ Variation of Domest. Anim. and Plants,’ ii, 165. 
