636 CONSERVATIVE ORGANS. [LECT. XI. 



spiral and proper vessels, which, apparently, ter- 

 minates in the substance of the gland. 



2. The knob-shaped gland, glandula clavifor- 

 mis, resembles a knob or a small nail, which, in 

 the language of the artisan, has not been driven 

 home. The head, which is the glandular part, is 

 slightly convex on the upper surface; and displays 

 a rough striated border, encircling a round flat 

 spot devoid of epidermis (Plate 9, fig. 31), from 

 which the secreted fluid is discharged. The in- 

 ternal structure of this gland closely resembles 

 that of the cup-shaped gland. It is generally 

 found either on the stem or the petiole of the leaf, 

 or on both in the same plant, as for instance in the 

 Castor-oil plant, Ricinus communis. 



3. The stipitate gland, glandula stipitata, is 

 so named from being supported on a long slender 

 stalk (Plate 9, fig. 15), and is, in fact, a stalked 

 variety of the cyathiform gland. It is the smallest 

 of the external glands, and is situated either on the 

 margin of leaves, as in Croton penicillatum ; or 

 on the disk, as in Sun-dew, Drosera rotundifolia. 



4. The branched pediculated gland, glandula 

 pediculata ramosa, is a small hemispherical gland 

 supported on a branched stalk (Plate 9, fig. 32). 

 The appearance of moss on the stem of the Moss 

 Rose is produced by glands of this description. 

 The individual glands are cellular, devoid of epi- 

 dermis, and each is furnished with vessels, which 

 are branches of a fasciculus, which enters the 



