STRUCTURE OF FLOWERS. 85 



of them. Thus a great number of apetalous plants are 

 so analogous in their whole symmetry to those furnished 

 with petals, that it is impossible not to think that their 

 absence is only owing to their non-development. Let 

 us observe here, that they are thus accidentally wanting 

 only in polypetalous flowers, and that there is no 

 authentic example known of an abortive corolla in 

 gamopetalous plants, if it be not so, perhaps, in some 

 cases where the stamens are wanting at the same time, 

 as in Gymnostyles and Fraxinus : when the petals are 

 abortive, there sometimes remains in their place either 

 a petaloid rudiment or a glandular body. We also say 

 that they are absent when they are accidentally changed 

 into stamens, as in the singular variety of Capsella 

 Bursa pastoris, of which M. De Jacquin has kindly 

 communicated to me a specimen and a drawing, which 

 I here give (PL 18, fig. 3, 4). In this monstrosity, 

 which can be perpetuated by seeds, we find the flowers 

 with ten stamens, instead of six of these organs and 

 four petals : I have found an analogous fact in a mon- 

 strosity of the common Bean, where the two wings of 

 the corolla were changed into stamens. We shall treat 

 more at length upon this kind of transformation, and 

 revert to the case where the petals are constantly wanting. 

 This will form the object of the following Section. 



