198 ON THE ASCLEPIADEiE. 



under surface there is no appearance of a suture, or any 

 indication of their having originally consisted of two distinct 

 parts : along with thera separate also the descending pro- 

 cesses, which are compressed, membranous, and light 

 brown ; their extremity, which is still unconnected, being 

 more gelatinous but not perceptibly thickened. The pollen 

 has acquired the yellow colour and the degree of consistence 

 which it afterwards retains. On the bursting of the cells, 

 the gelatinous extremity of each descending process becomes 

 firmly united with the upper attenuated end of the corre- 

 sponding mass of pollen. The parts are then in that con- 

 dition in which they have been commonly examined, and 

 are exhibited in the figures of Jacquin, who having seen 

 17] them only in this state, naturally considered these plants 

 as truly gynandrous, regarding the masses of pollen as the 

 antherae, originating in the glands of the stigma, and merely 

 immersed in the open cells of the genuine antherge, which 

 he calls antheriferous sacs ; an opinion in which he has been 

 followed by Rottboell, Koellreuter, Cavanilles, Smith, and 

 Desfontaines. The conclusion to be drawn from the ob- 

 servations now detailed is sufficiently obvious ; but it is 

 necessary to remark, that these observations do not entirely 

 apply to all the plants which I have referred to the Ascle- 

 piadese, some of them, especially Periploca, having a granular 

 pollen, applied in a very different manner to the glands of 

 the stigma : they all, however, agree in having pollen co- 

 alescing into masses, which are fixed or applied to processes 

 of the stigma, in a determinate manner,- and this is, in fact, 

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

 cond edition of his valuable " Introduction to Botany," has 

 noticed my opinion on this subject ; but, probably from an 

 indistinctness in the communication, which took place in 

 conversation, has stated it in a manner somewhat different 

 from what I intended 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 presents the idea of some- 

 thing indeterminate respecting the part to which the body 

 18] so projected may be applied. But nothing can be more 



