Greensill. — Leaf- structure of Coprosma. 345 



hairs are almost as broad as long ; their number varies. 

 Fig. 9 shows one of these hairs stained with eosine. The 

 nuclei (n.) and protoplasmic contents are then clearly seen. 

 In the young pit the hairs are unicellular, as in fig. 10. Next 

 to the epidermis are two layers of colourless round cells (c. /.), 

 next to which again is the ordinary spongy parenchyma of the 

 leaf. The chlorophyll cells that are present in the projecting 

 rims of the pit have fewer corpuscles, and are sometimes 

 almost colourless. This was the case in all the species I 

 examined. All the pits, too, had the same projecting rims 

 and circular outline. 



Coprosma propinqua. A. Cunningham, Precurs., n. 472. 



Fig. 22 shows the under-surface of a leaf of this species, 

 which, however, is rather broader-leaved than usual. The 

 pits are few in number ; sometimes one, sometimes two, and 

 occasionally none are present. The pits (p.) are in the axils 

 of the midrib (m.) and primary veins. The veins also are 

 few in number, as visible to the naked eve. The structure of 

 the leaf in transverse section (fig. 8) is as follows : On the 

 upper surface a rather thick cuticle (cu.) with minute irregular 

 projections ; an epidermis (ep.) of very large cells, almost 

 square in shape, which themselves can function as a storage 

 layer for water ; then two or three layers of palisade cells with 

 the usual contents, the chlorophyll corpuscles being irregu- 

 larly scattered. Then comes the spongy tissue of the leaf, 

 of the usual typical form, with slightly less numerous cor- 

 puscles than the palisade cells ; below that the epidermis of 

 the lower surface (I. ep.), of much smaller cells than that of 

 the upper, and with a thinner cuticle (cu.), which, however, 

 has the same irregular outline. In the lower epidermis are 

 numerous stomata (st.), which have much the same form as 

 those of Coprosma lucida, only the cuticle does not project so 

 much in front of the opening. The guard-cells (g.) are pear- 

 shaped, and the epidermal cells (s.) next to them are slightly 

 modified to fit into them. The epidermis of the pit (p. ep.) is 

 like that of the lower surface, though, of course, there are no 

 stomata ; the cuticle (cu.) has a very irregular outline. In 

 the pit are hairs (h.) of two, three, or sometimes more cells. 

 The individual cells of the hairs in this case are long and 

 narrow. 



Coprosma linearifolia. Hook, f., Handbk., 118. 



The upper and lower surfaces of the leaf are seen in 

 fig. 23. The upper surface shows no venation to the naked 

 eye ; the lower surface only the midrib and one or two primary 

 veins. The pit (p.) on the under-surface has a tiny opening; 

 on the upper a marked protuberance (pro.). The pits ap- 



