630 CONSERVATIVE ORGANS. [LECT. XI. 



tard, a French Phytologist, who first attempted 

 the subject, has been adopted by almost every 

 succeeding writer. He describes seven species of 

 vegetable glands : the miliary, the vesicular, the 

 scaly, the globular, the lenticular, the utricular, 

 and the cup-shaped; but as the cuticular aper- 

 tures, which he mistook for glands, constitute 

 his first species ; and the thin scales which cover 

 the fructification of the Ferns his third, there is 

 sufficient reason for rejecting this arrangement. 

 In attempting another, we must first take into 

 consideration the situation of these minute organs 

 as far as relates to their being under the cutis, 

 or exterior to it; and, consequently, I propose to 

 divide them into two classes, internal and external, 

 and to subdivide these into genera and species. 



A. The INTERNAL caulinar and foliar glands 

 are probably of various kinds, but one only, the 

 follicular, has yet been detected. 



1. The follicular gland, glandulafollicularis, 

 is in the form of a small sac or follicle. It is ge- 

 nerally found in the substance of leaves, and is 

 furnished with an excretory duct which opens upon 

 the under disk of the leaf. It is readily disco- 

 vered by its transparency, which gives the leaf a 

 punctured appearance when it is held up between 

 the eye and the light ; as exemplified in the leaves 

 of Perforated Saint John's Wort, Hypericum per- 

 foratum ; All Spice, Myrtus Pimenta ; the genus 



