142 STOMATES OF NEPENTHES, ETC. [BOOK i. 



concentric lines may be observed, indicating the compound 

 nature of the walls of the aperture. These stomates are 

 abundant on all surfaces of the young stems and branches, 

 but only on the lower surface of the older and horizontal 

 stems." (Flora Antarctica, vol. i. p. 291., where it is figured. 

 See also Elements of Botany, p. 21. fig. 69.) 



Nerium Oleander, and some other plants have, in lieu of 

 stomates, cavities in the cuticle, curiously filled up or pro- 

 tected by hairs. (See Annales des Sciences, xxi. 438.) 



In Nepenthes there are stomates of two kinds, the one 

 oblong, semi-transparent, and almost colourless, with numerous 

 pellucid globules in the cavity of the cells; the other roundish, 

 much more opaque, and coloured red. The latter do not 

 communicate immediately with internal cavities in the 

 parenchym, but are in contact with an internal deep 

 brownish-red gland, the lower side of which sometimes 

 appears to have six regular plane faces obliquely resting 

 upon a central face, or, in other cases, to be composed of six 

 cells surrounding a seventh, all being filled with dark red 

 colouring matter. The nature and use of these glands, and 

 of the stomates that accompany them, is unknown. This 

 is I believe the only case hitherto noticed, where the same 

 species has stomates of different forms ; it is also remarkable, 

 because in one of these cases the stomate does not open into 

 a chamber of the parenchym, but immediately reposes upon 

 a gland. 



Although the usual condition of stomates is such as is 

 above described, yet there are cases in which it is materially 

 modified, and their function is changed. An instance of 

 this occurs in Dionsea muscipula, in which the peculiar glands, 

 placed in great numbers on the upper side of the lamina of 

 the leaf, each proceed from a pair of parallel green cells, 

 apparently of the same nature as the two cells forming the 

 sphincter of a stomate. 



In the epidermis of certain plants are openings resembling 

 stomates, which require to be distinguished from them. In 

 Nuphar luteum they occur in the form of circular depressions 

 (figs, a and b), the sides of which are marked by elevated 

 rings. In Peperomia pereskisefolia (fig. e) they are deep 

 impressions in the epidermis, at the bottom of which is a 



