162 UTRICULAR AND INTERNAL GLANDS. [BOOK i. 



with its head is eventually developed ; h is a stalked 

 gland from the stem of the same plant ; i, a double- 

 headed gland from the flower stalk of Lysimachia 

 vulgaris. 



Compound Glands : c, a compound sessile gland of Dictam- 

 nus albus, consisting of a skin which is colourless, and 

 a centre which is filled with a thick green ethereal oil ; 

 /, compound glands from the flower stalk of Sanguisorba 

 carnea; k, a side view of the compound gland of the 

 hop, which chemists call Lupulin (Meyen entirely denies 

 the accuracy of Raspail/s description of this body) ; /, a 

 compound red gland from Ailanthus glandulosa ; m, 

 oblong stalked glands from Begonia platanifolia : they 

 resemble drops of resin. 



Other modifications of glandular apparatus are what some 

 Continental botanists call papulae, or papillae (fig. 16. e and n.) 

 (the Glandulae utriculares of Guettard); these are transparent 

 elevated points of the epidermis, filled with fluid, and cover- 

 ing closely the whole surface upon which they appear. In 

 other words, they are elevated, distended cells of the epider- 

 mis. The presence of papillae upon the leaves of the ice plant 

 gives rise to the peculiar crystalline nature of its surface. 



There are, moreover, in many plants internal glands, that 

 is to say, collections of cells densely compacted, and filled 

 with secreted matter which hardens them, or renders them 

 transparent. They are in some cases nearly of the nature of 

 cysts, already described. In Dictamnus albus they form 

 spherical nuclei, lying just below the cuticle, and filled with 

 an ethereal oil, rich in resin and camphor (fig. 10). In 

 Nepenthes they occur in two different states; the one as 

 angular nuclei below one of the forms of stomate found in 

 that plant ; the other as hard, deep brown discs, lining the 

 cavity of the pitcher, sunk below the epidermis, through 

 which there are openings corresponding with them, and no 

 doubt forming the apparatus by which the water contained 

 in the pitcher is secreted. They have been noticed and 

 figured by Meyen, but were long before mentioned in this 

 work (1835), and have been figured by me in the second 



