ON THE ASCLEPIADEJE. 17 



naturally considered these plants as truly gynan- 

 drous, regarding the masses of pollen as the an- 

 therae, originating in the glands of the stigma, and 

 merely immersed in the open cells of the genuine 

 antherae, which he calls antheriferous sacs ; an 

 opinion in which he has been followed by Rott- 

 boell, Koellreuter, Cavanilles, Smith, and Des- 

 fontaines. The conclusion to be drawn from the 

 observations now detailed, is sufficiently obvi- 

 ous but it is necessary to remark, that these ob- 

 servations do not entirely apply to all the plants 

 which I have referred to the Asclepiadeae, some of 

 them, especially Periploea, having a granular pol- 

 len, applied in a very different manner to the 

 glands of the stigma : they all, however, agree in 

 having pollen coalescing into masses, which are 

 fixed or applied to processes of the stigma, in a 

 determinate manner ; and this is. in fact, the essen- 

 tial character of the order. Dr Smith, in the se- 

 cond edition of his valuable ic Introduction to Bota- 

 ny," has noticed my opinion on this subject ; but, 

 probably from an indistinctness in the communi- 

 cation, which took place in conversation, has stated 

 it in a manner somewhat different from what I in- 

 tended to convey to him : For, according to his 

 statement, the pollen is projected on the stigma. 

 The term projection, however, seems to imply 

 some degree of impetus, and at the same time pre- 

 sents the idea of something indeterminate respect- 

 ing the part to which the body so projected may 



