344 Transactions. — Botany. 



above and phloem beneath. It has the usual structure, and 

 is accompanied by parenchymatous cells {"par.) and the leaf- 

 sheath (I. s.). Above the xylem are a few round chlorophyll- 

 containing cells (ch.), with few chlorophyll corpuscles (cfil.). 

 They are inserted between the xylem and the parenchyma 

 cells of the upper part of the leaf. In sections that have been 

 stained it is seen that the hairs and epidermis of the pit and 

 the colourless layers inside the epidermis have all living 

 protoplasmic contents. This was the case in every species 

 examined, in which all or any of these cells were present. 



Fig. 3 is a surface section of the pit showing the stomata 

 in surface view, and the position of the pit between the mid- 

 rib (m.) and the primary veins. The epidermis of the pit 

 (p. ep.) is seen, the hairs (h.), and the colourless layers (c. I.) 

 inside the epidermis. The characters already mentioned are 

 thus repeated in this section, though the shape of the cells 

 differs in correspondence to the different direction in which 

 the section was cut. 



Coprosma lucida. Forster, Char. Gen., 138. 



The pits (p.) are situated in the axils of the midrib (m.) and 

 primary veins, and occur with great regularity. I saw none 

 in the axils of the secondary veins. The two leaves figured 

 (figs. 5 and 11) are both varieties of this species. The struc- 

 ture of the tissues as seen in transverse section (fig. 6) is as 

 follows : On the upper surface of the leaf a thick cuticle (cu.) 

 with a wavy outline ; an epidermal layer (ep.) of narrow cells 

 elongated in a transverse direction ; then a hypodermal layer 

 of roundish cells (st. I.), also elongated in a transverse direc- 

 tion, and serving as a storage layer for water; then two or 

 three layers of typical palisade cells (p.p.), with chlorophyll 

 corpuscles (chl.) and drops of oil (d.). The chlorophyll cor- 

 puscles in this case are less crowded, though still numerous. 

 Next comes typical spongy parenchyma (sp.) of irregularly 

 shaped cells, with chlorophyll corpuscles scattered in them. 

 This, as usual in all the species, occupied the greatest thick- 

 ness of the leaf. Below this is the epidermis of the lower 

 surface (I. ep.), the cells of which are smaller and broader 

 than those of the upper ; then a cuticle, thinner, but with the 

 wavy outline of that on the upper surface. In the lower 

 epidermis are numerous stomata (st.) with small guard- 

 cells (g.), and subsidiary cells (s.), not so unlike ordinary 

 epidermal cells. The cuticle forms a projection (p.) at the 

 entrance of the stoma, thus narrowing it and diminishing the 

 rate of transpiration. The epidermis (p. ep.) and cuticle (cu.) 

 of the pit are continuous with and similar to those of the 

 lower surface. There are numerous multicellular hairs (h.) 

 in the pit or at its mouth. The individual cells of these 





