564 
EXPLANATION OF THE PLATES. 
Fig. 12. A longitudinal section of a portion of a stem, showing various kinds of 
tissue : a and g, tubes of cinenchyma or laticiferous tissue ; 6, cylindrical 
parenchyma; c, an annular duct; d, an annular duct of Jarger size, with its 
spires more broken ; e, cylindrical parenchyma containing amylaceous gra- 
nules ; f, a reticulated duct ; h, oblong parenchyma containing amylaceous 
granules. 
Fig. 13. Joints of a hair, showing the capillary cinenchyma in which cyclosis 
takes place ; a, cytoblasts ; the arrows indicate the direction of the currents. 
Fig. 14. Two joints of a hair of Tradescantia in a dead state, to show the col- 
lapsed appearance of the cells (h b) which are enclosed wdthin the external 
cavity of organic mucus, and over which the currents of cyclosis are main- 
tained ; a, a cytoblast. 
Fig. 15. A bundle of closed ducts from the stem of a Lycopodium ; after a pre- 
paration by Mr. Griffith. Here is seen the manner in v/hich such vessels are 
packed in situ, together with their terminations. 
Fig. 16. A portion of cinenchyma, or laticiferous tissue, from the stipule of the 
Ficus elastica, showing the anastomoses ; after Schultz. 
Fig. 17. One of the anastomoses of cinenchyma, surrounded by thin-sided oblong 
parenchyma. 
Fig. 18. A stinging hair, in which cyclosis is going on, the direction of the cur- 
rents being indicated by arrows. 
Fig. 19. An anastomosis in the cinenchyma of a Euphorbia, with two of the 
double-headed bodies supposed to be amylaceous ; a a represent the mouths 
of the cinenchyma. 
Fig. 20. Glandular pleurenchyma of Sphaerostema propinquum. 
PLATE III. 
Fig. 1. A cluster of six-sided air-cells from the stem of Limnocharis Plumieri ; 
they are formed entirely of prismatical cells ; a a, partitions dividing the air- 
cells in two. 
Fig. 2. A partition or diaphragm of the last-mentioned plant, showing the open 
passages that exist at the angles of the cells. When dry, the rims of the 
passages are dark, as at a ; when immersed in water, the dark rim disappears, 
and the whole partition has the uniform appearance of h. 
Fig. 3. A portion of the epidermis, and a stoma, of the leaf of Oncidium altissi- 
mum; a, the stoma, formed of two parallel glands or cells, which open by 
curving outwards. In this plant the stomata are very minute and few ; on 
the membrane of each mesh of the epidermis are found sticking from four to 
six spherical semi-transparent green globules. 
Fig. 4. Stomata of Strobilanthes Sabiniana. They are very large, and crowded 
together in an irregular manner. 
Fig. 5. Ditto of Croton variegatum : this is an instance of an epidermis with 
sinuous lines. The orifice of each stoma is closed up with brownish matter. 
Fig. 6. A stoma of Canna iridiflora. 
Fig. 7. A cavity beneath the epidermis, in the parenchyma of Begonia sanguinea 
seen from the inside, so that the epidermis is farthest from the eye. It is 
divided by sub-cylindrical cellules into five spaces, in each of which there lies 
a stoma. 
