348 Transactions. — Botany. 



the midrib (in.) and primary veins. The venation is reticu- 

 late, the leaf thin and hairy, and the pits (p.), with tufts of 

 hairs projecting from the opening, easily visible to the naked 

 eye. The structure of the leaf in transverse section is very 

 similar to that of Goprosma chathamica. It is seen in fig. 17. 

 On tbe upper surface a cuticle (cu.) with slightly irregular 

 outline ; an epidermis (ep.) of cells elongated in a transverse 

 direction ; two or three layers of typical palisade cells (p. p.), 

 with chlorophyll corpuscles (chl.) arranged regularly along 

 the walls of the cells ; below that spongy tissue, the cells of 

 which are rounded, and scarcely irregular at all in shape. 

 They contain chlorophyll corpuscles arranged along the walls 

 of the cells. On the lower surface is an epidermis (l. ep.) of 

 smaller cells, with a thin cuticle. The layer of cells next to 

 the epidermis contains very few chlorophyll corpuscles. On 

 the lower surface are numerous stomata (st.) with pear-shaped 

 guard-cells (g.), and slightly modified subsidiary cells (s.). 

 There are many hairs (h.) at the mouth of the pit, which pro- 

 ject in tufts. They are multicellular, and some are very 

 long ; the individual cells of the hairs are elongated and 

 narrow. The epidermis (p. ep.) and cuticle are similar to 

 those of the lower surface. Next to the pit epidermis are 

 two layers of colourless cells (c. I.), roundish in shape, and 

 slightly elongated in a transverse direction. In this case the 

 layer (x.) of Goprosma chathamica has been fully modified to 

 form a second colourless layer. Around these colourless cells 

 is the spongy tissue of the leaf. There are hairs (h.) also 

 within the pit, but they are not so numerous nor so long as 

 those at the opening. On the upper and lower surfaces of 

 the leaf also there are numerous hairs, mostly two-celled, 

 though they may consist of more cells, or be unicellular. 

 They are especially numerous proceeding from the epidermis 

 next to the parenchymatous cells (par.) surrounding a 

 vascular bundle. Both of these Chatham Island species 

 have less projecting rims to their pits. 



Coprosma robusta. Eaoul., in Ann. Sc. Nat., ii. (1844), 121. 



The under-surface of the leaf is shown in fig. 19. The 

 venation is reticulate. The pits (p.) are regularly arranged 

 in the axils of the midrib (m.) and primary veins. On the 

 upper surface their presence is indicated by a well-marked 

 protuberance. The structure in transverse section (fig. 18) 

 is as follows : On the upper surface a rather thick cuticle (cu.) 

 with slightly irregular outline ; an epidermis (ep.) of roundish 

 cells, large and elongated in a transverse direction, and pro- 

 bably serving to store up water in addition to their other 

 functions. Beneath the epidermis are two or three layers of 

 typical palisade cells with the usual contents, the chloro- 



