HETEROTAXY. 



181 



flower-bud for an ovule or from prolification ; there are 

 certain cases, however, where the new growth seems 

 not to be either due to metamorphosis or to prolifi- 

 cation strictly. 



The cut, fig. 94, represents a case where, in the 

 dilated upper portion of the ovary of Sinapis arvensifij 



ViQ. 94. Distended pod of Sinapis arvensis bearing in the interioi- 

 stalked flower buds. 



two flower-buds were found projecting from a raised 

 central line, corresponding, as it would seem, to the 

 midrib, and not to the margins of the carpel. Similar 

 cases have occurred in Nasturtium amphihium, Brassica 

 Bapaj and Passiflora quadrangulans. 



In Bromfield's ' Flora Vectensis,' p. 35, the foUo^Nnng 

 account is given of an abnormal development in Carda- 

 mine pratensis : " On the lower part of the corymb 

 were several seed vessels on pedicels changed from 

 their usual linear to an ovate elliptical figure, so as to 

 resemble a silicula. These, on being opened, were 

 found to contain petals of the usual colour, which in 

 the pods above had burst from their confinement and 

 appeared as semi-double flowers ; the valves of the pod 

 answering to the true calyx. * * * From their verti- 

 cillate arrangement it is evident that these petaloid 

 expansions were not transformed seeds, but simply a 

 development of the common axis within the ovary into 

 an abortive whorl of floral organs, besides which there 

 were Evident rudiments both of stamens and gerraens 



