and on various Plants related to them. 329 



two distinct cases of monstrosities affecting two Leguminous plants, both, I 

 believe, species of Melilotus, the stigmatic surface is evidently a continuation 



point of view, as determining the limits of families, and theoretically, in ascertaining the true compo- 

 sition of organs, than those derived from the analogous differences in the ovaria or placentae." 



This jiaper I may be permitted to consider as of the highest importance, more particularly as it ad- 

 vocates the opinion that " ovula belong to the transformed leaf or carpel, and are not derived from 

 processes of the axis united with it, as several eminent botanists have lately supposed ; " which opi- 

 nion M. Schleiden, with whom the hypothesis of the origin from the axis commenced, has stated to be 

 an " extravagant view founded on the weakest possible grounds." 



Forcible arguments are added to those formerly published by the same great master in opposition to 

 the hypothesis now chiefly supported by Dr. Lindley of the carpellary structure of Orchidea, which 

 hypothesis is clearly shown to be contrary to every analogy. 



The only argument in favour of the existence of six carpella in Orchideee, but by no means in favour 

 of the above hypothesis, seems to me that presented by Vanilla planifolia, as represented by Mr. Francis 

 Bauer', in which the appearances seem to me those of an unilocular pistillum composed of six carpella 

 with marginal ordinarily compound placentae. This structure however does not exist in a Malayan 

 undescribed species, the only one I have been able to examine^, in which there are six simple placentae, 

 with a tendency to approximation by pairs. This separation of the placentae, so generally combined 

 in compound pairs, I would explain by assuming a certain amount of growth of the interplacentar 

 parts of the compound ovarium, an assumption perhaps derivable from the consideration of Euhalus 

 and certain Orobancheee. Among the drawings in the Botanic Garden, I find a sketch of an Oro- 

 bancheous plant (without name or any clue to what it may be), in which the appearances are exactly 

 those of an unilocular quadricarpellary ovarium. 



Mr. Brown's paper may be considered as disposing finally of many of the apparently anomalous cases, 

 whether the supposed anomaly has been suggested by the examination of the stigma or ovarium. His 

 explanation of Cruciferte is, in accordance with his previous ideas, extended to the stigma, perhaps to 

 account for its opposition to the placentae, on which great stress had been laid. The few observations 

 I have made on one genus only of this family appear to me to indicate the probability, that in some 

 genera, at least, the pistillum is composed of four carpella ; the stigmata of each of the anterior and 

 posterior carpella (which subsequently are much the smallest) being confluent, and also cohering with 

 the stigmata of the lateral carpella, which are individually otherwise distinct. This structure, so far 

 as the pistillum is concerned, is analogous in a considerable degree to that of Chryseis. The above 

 explanation, founded on a solitary instance, is independent of that by Professor Lindley, suggested by 

 the plant just mentioned', in which the anomaly is assumed to exist from the opposition of the stigmata 

 to the placentae, which is, I believe, their true theoretical situation. 



The apparently anomalous structure of Cucurbiiaceee, to which notice has been lately directed by 



1 Gen. Sp. Orchid, part 3. t. 10. 



* I have since examined one ovarium of Vanilla planifolia, and this specimen did not present to me 

 appearances different in any important degree from those of the Malacca plants. 

 ' Bot. Register, t. 1168, sub Eschscholtzia calif ornica. 



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