certain vegetable Muscicap<e. lit 



reach the stigma are necessarily entrapped in the ascidia. 

 But I know not what may b« the final intention of Nature 

 in giving the peculiar odour which I have mentioned to 

 the stigma of Sarracenia Jiava and some other species of 

 the genus. Those philosophers* who imagine that there 

 are some plants which cannot be impregnated without the 

 aid of insects, may perhaps fancy that they have discovered 

 Nature's ulterior object in the present instance. Indeed, 

 I confess myself at a loss to conceive how, in some of 

 the species of Sarracenia, the pollen or fecundatina; in- 

 fluence of the stamens can reach the upper surface of the 

 stigma. See in my Elements of Botany, and in other 

 works, the figure oi Sarracenia purpurea. — And I presume, 

 that it is certainly upon the upper surface of the stigma of 

 these plants' that the pollen, or at least its favilla, mtist be 

 applied, in .order to enlarge and render fertile the embrya 

 seeds. In the Sarracenice, the aid of insects in giving fer- 

 tility to the gernjen or ovarium may possibly be necessary. 

 I think it cannot be much less necessary (if at all less ne- 

 cessary) in Sarracenia purpurea, than it is said by Mr.VVil!- 

 denow. Dr. J. E. Smith, and other respectable botanists, to 

 be in AristolocJda Clematitis. — See Willdenow's Principles 

 of Botany and of Vegetable Physiology, English translation, 

 pages 316— 318. Edinburgh, \&05\~. But although I believe 

 in the doctrine of the sexes of plants as a general doctrine, 

 I am compelled by many facts and consideration^ to doubt 

 whether the impregnation of any vecetable is ■necessarily 

 dependent upon insectile aid J. On this curious subject 

 I shall offer something more specific in my "Memoirs ot» 

 the Origin and Progress of our Knowledge concerning the 

 Sexes of Vegetables." 



But there is still a much more considerable and obviou;* 



* Linnxus, Sprenge!, Willdenow, Smith. 



•f- See also Dr. Smith's Ictroduction to Botany, &c. page 3fi7, &c. I>ordot! 

 1807. This botanist not only reposes confidence in Willdenow's thtorv ol 

 the insectile impregnation of Aristulochia Clemalilis, but he thinks it pro- 

 bable that " for wai/t of some insect adapted to the same purpose in its own 

 country, the Americin Am-Uihchia Sijjlio, thouj^h it flowers plentifully, never 

 forms fruit " in the British gardens. However it may be in /Iristohchia Clt- 

 maiUis, I am persu.ided that insects are not necessary agents in the impreg- 

 nation of the germ ot ArisUdoihiaSiplio, or " Dutchm.in's-Pipe," as it is calL-d 

 in Pennsylvania. I am well acquainted with this plant, and cannot perceive 

 from the structure and disposition of its genitalia any obstacle to the appli- 

 cation of the pollen to the female organ. Certainly, there is much 'ess difli- 

 culty Ml conceiving how impregnation is elFected in this Anstnlochiu, than in 

 htindrcds of other plants, concerning the impregnation of which no diffi- 

 culties have ever occurred in the minds of botanists. 



i •' I'he dichogamic plants can be in no other w,iy fecundated than by in- 

 sects." — W 'lllJeiiuu: 



cause 



