212 Mr. Brown's Account of a new Genus of Plants, 



The structure now described actually exists in many families 

 of plants ; and the principal deviations from it may be stated to 

 depend either on a reduced or increased development of the 

 parts enumerated, on differences in the manner of bursting, or 

 on the confluence of two or more antherse. 



Reduced development may consist merely in the approxima- 

 tion of the thecae, consequent on the narrowing or entire absence 

 of the connecting portion of the filament, which is one of the 

 most common states of anthera ; in their partial confluence, 

 generally at the upper extremity ; their parallelism either con- 

 tinuing, 



In the Anthera, which are seldom compound, and whose thecse are usually distinct, 

 the marginal production of pollen is generally obvious. 



In the Ovaria, however, where, with very few exceptions, the same arrangement of 

 ovula really exists, it is never apparent, but is always more or less concealed either by 

 the approximation and union of the opposite margins of the simple pistillum, and of 

 the compound when multilocular; or in the unilocular pistillum with several parietal 

 placentae by the union of the corresponding margins of its component parts. 



The few cases of apparent exception, where the ovula are inserted over the whole or 

 greater part of the internal surface of the ovarium, occur either in the compound- pistil- 

 lum, as in Nympfuca and Nuphar ; or in the simple pistillum, as in Biitomea of Richard ; 

 and in Lardizabalea, an order of plants sufficiently distinct in this remarkable character 

 alone, and differing also in the structure of embryo and in habit, from Menispermea, to 

 which the genera composing \t(Lardizaba!a and Stauntonia)hzve hitherto been referred. 



The marginal production of ovula, though always concealed in the ordinary or com- 

 plete state of the Ovarium, not unfrequently becomes apparent where its formation is 

 in some degree imperfect, and is most evident in those deviations from regular structure, 

 where stamina are changed, more or less completely, into pistilla. Thus, in the case of 

 the nearly distinct or simple pistillum, it is shown by this kind of monstrosity in Sernper- 

 vivum iectorum ; in the compound multilocular pistillum, by that of Tropccolum maius ; 

 and in the compound pistillum with parietal placentas, by similar changes in Cheiranlhus 

 Cheiri, Cochlearia armoracia, Papaver nudicaule and Salix olei folia. 



In all the cases now quoted, and in several others with which I am acquainted, it is 

 ascertained that a single stamen is converted into a simple pistillum, or into one of the 

 constituent parts of the compound organ : a fact which in my opinion establishes the 

 proposed type of Ovarium. 



I have 



