IN ORCHIDEiE AXD ASCLEPIADE^. 503 



tliat dehiscence which, though very remarkable in this order, 

 is in a great degree analogous to that taking pkace in most 

 Cruciferee, in several Leguminosa', and in otlier families of 

 plants. It may also be objected to j\Ir. Bauer's view of 

 tlie composition of ovarium, that the arrangement of the 

 parietal placentae, which on this hypothesis would occupy 

 the axes of the three alternate comi)onent parts, is contrary 

 to every analogy ; Avhile the position of the stigmata, if my 

 account should prove to be correct, affords evidence nearly 

 conclusive of the ovarium being formed of only three parts. 



In those genera of OrchidccC in Avhich the lateral stamina 

 are perfect, and the middle stamen without anthera, namely, 

 Cypripedium and Apostasia, all these lobes or divisions of 

 stigma are equally developed, are of nearly similar form 

 and texture, and, as I have proved by direct experiment in 

 Cypripedium, are all equally capable of performing the 

 proper function of the organ. 



In most other cases the anterior lobe, or that placed croi 

 opposite to the perfect stamen, and deriving its vessels from 

 the same cord, manifestly differs both in form and texture 

 from the other two. To this anterior, or upper lobe, as it 

 generally becomes in the expanded flower, the glands always 

 belong to which the pollen masses become attached, but 

 from w^hicli they are in all cases originally distinct, as may 

 be proved even in Ophrydea?. 



According to my view, therefore, of the mode of impreg- 

 nation, its office is essentially dift'erent from that of the 

 two lateral lobes or stigmata, which in various degrees of 

 development are always present, and in all cases, when the 

 ovarium is perfect, are capable of performing their proper 

 function. 



The greatest development of these lateral stigmata takes 

 place in the tribe of Satyrinac or Ophrydeac, as in many 

 species of Ilahenaria, those especially which are found 

 near or within the tropics ; and still more remarkably in 

 Bonatea sjieciosa, a plant hardly indeed distinguishable 

 from the same extensive genus. 



It would seem that in Bonatea the extraordinary develop- 

 ment and complete separation of these lateral stigmata. 



