M. Ad, Brongniart on Vegetable Morphology. 



LVII. — Examination of some instances of Vegetable Monstro- 

 sities, elucidating the Structure of the Pistil and the Origin of 

 Ovules. By M. Ad. Brongniart*. 



While some botanists contend that the placenta is a prolonga- 

 tion of the central, or an axillary axis applied upon or united to 

 the carpellary leaf, others maintain that the ovules are only 

 modifications of appendages, or even parts of the carpellary leaves 

 themselves. In confirmation of the latter view, M. Ad. Bron- 

 gniart cites an instance of monstrosity observed by him in Del- 

 phinium elatum cultivated at the Museum of Natural History at 

 Paris in 1841, in which the carpels underwent all degrees of 

 foliaceous transformation, presenting on their borders ovules, 

 sometimes normal, sometimes passing insensibly into the state of 

 lateral lobes of the carpellary leaf itself. 



The most important monstrosity (observed among many 

 others) was that in which the carpellary leaves formed, toward 

 their summit, an ovary closed by the junction of the carpellary 

 leaves bearing ovules scarcely altered, and presented at their 

 inferior part a leaf whose borders were lobed, folded inwards, 

 separated from each other, and destitute of ovules. On the bor- 

 ders of these carpels were observed all states of transition from 

 lateral trifid lobes of the leaf to true ovules. 



It was seen that the carpellary leaves were traversed by three 

 principal longitudinal nervures, one median and two lateral ; the 

 latter corresponding to the margins of the carpellary leaf such 

 as it existed in unaltered pistils, these margins by their union 

 constituting the internal suture of the carpels ; that the wall of 

 the ovary was only constituted of that portion of the leaf com- 

 prehended between the median and lateral nerves, while the 

 portion of the leaf outside the lateral nerves formed no part of 

 the ovary, but was transformed into ovules. The transformation 

 was evident, as these lobes were not abortive and ovules developed 

 in their place, but they became smaller, curved and folded upon 

 themselves, so as to constitute the funiculus and primine, or 

 external membrane of the ovule. 



It was easily seen, that of the three teeth each of these lobules 

 preseiited, the lateral became atrophied, the base of the lobe 

 narrowing to form the very short funiculus of the ovule, while 

 the middle part of each lobe was hollowed and curved upwards 

 and inwards in the form of a hood, so as to constitute the pri- 

 mine. As to the nucleus, it originated from a sort of cellular 

 excrescence or papilla situated on the upper surface upon the 

 median nerve of each lobe a little below its summit. In the 

 lobes spread out and not participating in the formation of tegu- 



* Abstract from the Comptes Rendus, tome xviii. No. 13, 25 Mars 1844, 

 communicated by A. Henfrey, Esq. 



