392 



Fig. 8. A profile view of the same. 



Fig. 9. A simple or one-threaded spiral vessel, partly unrolled, with its 



termination. 

 Fig. 10. A bent portion of the spire of the latter, to show that elementary fibre 



is cylindrical. 

 Fig. 11. A compound or many- threaded spiral vessel, partly unrolled, with its 



terminations. 

 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 larger size, with 



its spires more broken ; e, cylindrical parenchyma containing amylaceous 



granules ; /, a reticulated duct ; h, oblong parenchyma containing amylaceous 



granules. 

 Fig. 1 3. Joints of a hair, showing the capillary branches from the cytoblast in 



which circulation takes place ; a, cytoblasts ; the arrows indicate the 



direction of the currents. 

 Fig. 1 4. Two joints of a hair of Tradescantia in a dead state, to show the collapsed 



appearance of the protoplasm enclosed within the external cavity or cell 



wall, and over which the currents of motion are maintained ; a, a 



cytoblast. 

 Fig. 15. A bundle of closed ducts from the stem of a Lycopodiumj after a 



preparation by Mr. Griffith. Here is seen the manner in which 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 circulation is going on, the direction of the 



currents 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 j a a represent the mouths 



of the cinenchyma. 

 Fig. 20. Glandular pleurenchyma of Sphserostema propinquum. 



PLATE III. 



Fig. ] . 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 b. 



Fig. 3. A portion of the epidermis, and a stoma, of the leaf of Oncidium 

 altissimum ; 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. 



