BY ALEX. G. HAMILTON. 769 



(5) A thick layer of spongy parenchyma, arranged in a network, 

 but very closely, and with few intercellular spaces, and these 

 very small. The cells of this layer are small. At the sides of 

 the cavity they are larger and looser in arrangement, so that the 

 perimeter of the cavity is surrounded by this more open network of 

 cells, which gradually passes into the ordinary spongy parenchyma 

 of the rest of the leaf. Here the intercellular spaces are regularly 

 arranged, and extend from the lower epidermis to the palisade- 

 tissue. These cells also have very many chloroplasts, and those 

 nearest to the palisade cells lla^■e the oil globules above mentioned. 

 But there are none of the tannin-sacs noted in Pennatitla, and in 

 the densest part they are never arranged like brickwork as in 

 that species. 



(6) A single layer of epidermis, the cells thick-walled, and the 

 cavity circular in outline. From this j^roceed the unicellular 

 thick-walled hairs springing from much enlarged cells, and some- 

 times but rarely septate. 



(7) The cuticle of the inside continuous with that of the lower 

 side of the leaf. No stomata occur in the cavity, but they are 

 found up to the very margin of the orifice. Vascular bundles 

 occur in the spongy parenchyma all round the cavity. 



In the floor of the cavity all these layers except the palisade- 

 tissue and the hypoderma occur in reversed order. The develop- 

 ment of the domatia in young leaves takes place much as in 

 Peniiantia, but the unicellular hairs appear later, only the 4-celled 

 hairs being present at first. 



The points of resemblance between Pennantia and Coprosma 

 are the dense spongy parenchyma over the roof and round the 

 cavity, and the epidermal hairs inside and at. the mouth. The 

 differences are the occurrence of tannin-sacs in Pennantia and not 

 in Coprosma, and the non-occurrence of oil globules in the cells, 

 and of hairs on the outside of the leaves in the formeT-. 



Coprosma fcetidissima, Forst. — I have seen dried leaves only 

 of this and the following seven species, and am not able therefore 

 to give particulars of the minute structure. In this species the 

 domatia are in the axils of the second and third pairs of veins 



