368 STIGMA. [BOOK. i. 



approximated to all the vascular cord of the axis, it has by 

 some botanists been considered as actually derived from it/ 

 which it is, however, only in the same manner as the mar- 

 ginal placentae are derived from the axis of the carpel. But 

 according to the notion now advanced, each simple pistillum 

 or carpel has necessarily two stigmata, which are to be 

 regarded, not as terminal, but lateral. 



That the stigma is always lateral may be inferred from its 

 being obviously so in many cases ; and in one genus at least, 

 Tasmannia, it extends nearly the whole length of the ovarium, 

 so as to be commensurate with and placed exactly opposite 

 to the internal polyspermous placenta. 



That the stigma is always double appears probable, from 

 those cases ir^ which it is either completely developed, as in 

 the greater part of Graminese where the ovarium is simple ; 

 in the compound ovarium in Urena ; and from those in which 

 the development, though less complete, is still sufficiently 

 obvious, as in many Euphorbiacese and in several Iridese. 

 This degree of development, however, is comparatively rare, 

 confluence between the two stigmata of each carpel being 

 the more usual structure ; and in the compound pistillum a 

 greater degree of confluence often takes place in the stigmata 

 than in the placentae; a fact, which in all such cases is 

 obviously connected with adaptation of surface to the more 

 complete performance of function." 



Nothing is, properly speaking, stigma, except the secreting 

 surface of the style ; it very often, however, happens, that 

 the term is carelessly applied to other portions of the style. 

 For example, in the genus Iris, the three petaloid lobed 

 styles in the centre are called stigmata ; while the stigma is 

 in reality confined to a narrow transverse humid space at the 

 back of each style : in Labiates, Bentham has shown that 

 what is called a two-lobed stigma, is a two-lobed style, the 

 points only of the lobes of which are stigmatic : and in 

 Lathyrus, and many other papilionaceous plants, Linnean 

 botanists call the hairy back of the style the stigma; while, 

 in fact, the latter is confined to the mere point of the style. 



Nevertheless, there are certain stigmas in which no denuded 

 or secreting surface can be detected. Of this nature is that 



