702 Mr. Brown on the Organs and Mode of 



description of stigma which, in 1813, I introduced into the 

 character of Satyrium*, implies an analogous development in 

 that genus. 



On the relative position of stamina and stigmata in the column 

 of an Orchideous plant, it may be remarked that there is hardly 

 an instance of a perfectly developed stamen and stigma placed 

 opposite to each other, and consequently deriving their vessels 

 from the same cord. 



For, in the ordinary structure of the family in which only one 

 perfect stamen is produced, the corresponding stigma loses 

 entirely or in great part its proper function, which it recovers, 

 so to speak, in those cases where this stamen becomes imperfect, 

 or is destitute of an anthera : and hence, perhaps, it may be said 

 that to obtain in any case the complete development of the 

 lateral stamina, and, what is of greater importance, to ensure 

 in all cases the perfection of the lateral stigmata, these organs 

 are never placed opposite, but uniformly alternate with each 

 other. 



The general conformation of the ovarium, with regard to the 

 number and relative position of the parietal placentae, and the 

 arrangement of their numerous ovula, has long been well under- 

 stood. But the early structure and evolution of the unimpreg- 

 nated ovulum have not yet, as far as I know, been in any 

 degree attended to. 



In its gradual development, the ovulum exhibits a series 

 of changes nearly agreeing with those which M. Mirbelt has 

 described and illustrated as taking place in other families. 



In the earliest state in which I have examined the ovulum in 

 Orchideae, it consists merely of a minute papilla projecting 



* Ait. Hort. Kew. ed. 2. vol. v. p. 196. 



f Annul, des Sc. Nat. xvii. p. 302. ; — and in Mem. de PAcad. des Sc. de I'Instit. ix. 

 p. 212. 



from 



