MULTICELLULAR GLANDULAR HAIRS =Multicellular glandular hairs= are divided into two groups: first, sessile; and secondly, stalked hairs. Multicellular sessile glandular hairs occur on the leaves of peppermint (Plate 60, Fig. 3), horehound (Plate 97, Fig. 7), and in hops (Plate 60, Fig. 4). In each of these hairs there are eight secretion cells. =Stalked glandular hairs= are divided into two groups: first, uniseriate stalked; and secondly, multiseriate stalked glandular hairs. =Multicellular uniseriate stalked glandular hairs= occur on the leaves of tobacco (Plate 61, Fig. 4), belladonna (Plate 61, Fig. 1), and digitalis (Plate 60, Fig. 2), and of the fruit of rhus glabra. [Illustration: PLATE 60 GLANDULAR HAIRS 1. Kamala (_Mallotus philippinensis_, [Lam.] [Muell.] Arg.). 2. Digitalis leaf (_Digitalis purpurea_, L.). 3. Peppermint leaf (_Mentha piperita_, L.). 4. Lupulin. 5. Cannabis indica leaf (_Cannabis saliva_, L.).] =Multicellular multiseriate stalked glandular hairs= occur on the stems and leaves of cannabis indica (Plate 60, Fig. 5). In the glandular hair of kamala (Plate 60, Fig. 1) the number of secretion cells is variable and papillate in form, and the cuticle is separated from the secretion cells. In the glandular hair of hops the outer wall or cuticle is torn away from the secretion cells, and the cavity thus formed serves as a storage cavity. This distended cuticle of the hops shows the outline of the cells from which it was separated. In the glandular hairs of the mints the secreted products (volatile oils) are stored between the secretion cells and the outer detached cuticle. This cuticle is elastic, and it becomes greatly distended as the volatile oil increases in amount. In many of the so-called glandular hairs, tobacco, belladonna geranium, etc., the synthetic products are retained in the glandular cells, there being no special cavity for their storage. These hairs usually contain an abundance of chlorophyll. The division wall of multicellular glandular hairs may be vertical, as in the two-celled hair of digitalis (Plate 60, Fig. 2); as in horehound (Plate 97, Fig. 6), and as in peppermint (Plate 60, Fig. 3); in this case there are eight cells, and they form a more or less flat plate of cells. In other hairs the division wall is horizontal; this produces a chain of superimposed secreting cells, as in some of the glandular hairs of belladonna leaf (Plate 61, Fig. 1), etc. In other hairs the division walls are both vertical and horizontal, as in tobacco (Plate 61, Fig. 4), henbane (Plate 61, Fig. 3), belladonna (Plate 61, Fig. 1). Other characters to be kept in mind in studying glandular hairs are the following: Color of cell contents; size of the cells, whether uniform or variable; character of wall, whether smooth or rough. SECRETION CAVITIES