232 Transactions. 



confined to the lower surface : the guard-cells are small and on the same 

 level as the other epidermal cells, the stoma being protected by guard-cell 

 ridges. On the lower surface there are hydathodes, which are sunk in slight 

 depressions. 



The chlorenchyma is differentiated into palisade and spongy tissue. 

 The former consists of 3 rows of thin-walled cells, the outer layer with 

 the cells very closely arranged so that there are no intercellular spaces : 

 the 2 inner layers are arranged more loosely. The spongy tissue consists 

 of small thin -walled irregular cells which have rather small air-spaces 

 between them. Manv of the chlorenchymatous cells contain tannin. 



The midrib is slightly prominent. Surrounding the vascular bundle of 

 the midrib there is a sheath 1-3 cells thick, consisting of small sclerenchy- 

 matous cells. Around this there is a sheath of larger cells, also with 

 lignified walls. The xylem consists of vessels of moderately large diameter 

 and of wood-fibres. Above the xylem there is a small amount of parenchyma. 

 The phloem is in the form of a crescent : the parenchymatous elements 

 contain tannin. 



Stem.- The cork is a fairly wide band of tissue, consisting of small, very 

 compact cells. 



The cortical cells are large, and oval in transverse section. These cells 

 are thick-walled, and many of them contain tannin. They are closely 

 arranged, so that there are only small intercellular air-spaces. 



The pericycle fibres form a wide band, in which the cells vary consider- 

 ablv in size in transverse section. Some are small, with their cell-walls so 

 much lignified and thickened that the lumen is almost obliterated ; con- 

 necting groups of these cells are much larger cells, also with thickened, 

 lignified walls, but the cell-cavities are large. 



The phloem forms a narrow band, and the parenchyma contains tannin. 

 The spring wood consists of a large number of vessels of large diameter, 

 together with wood-fibres. The autumn wood is formed of much smaller 

 vessels, and of wood-fibres in which the lumen is almost obliterated. 



The medullary rays are uniseriate, and the cells have thickened lignified 

 walls, and contain tannin. The pith cells are large and round, have thick- 

 ened lignified walls, and contain abundant starch. 



2. Nothofagus cliffortioides Oerst. 



Usual Growth-form- "A small tree, usually from 20ft. to 40ft. high, 

 rarely more, with a trunk 1-2 ft. diani., in alpine localities often dwarfed 

 into a much-branched bush 5-12 ft. high. Branches spreading, often dis- 

 tichous, especially in young trees : branchlets densely pubescent. Leaves 

 shortly petiolate, distichous, |-| in. long, ovate-oblong or ovate or ovate- 

 orbicular, acute or subacute, rarely obtuse, always broadest at the unequally 

 rounded or almost cordate base, quite entire, very coriaceous, glabrous 

 and reticulated above, more or less clothed with greyish-white appressed 

 hairs beneath, margins thickened, often recurved ; stipules membranous, 

 caducous." 



Mineral Belt Growth-form. A much-branched bush 4 8 ft. high, with 

 leaves \-\ in. long. 



Anatomy. 



Leaf.— The upper epidermis consists of small cells which are more or 

 less square in transverse section. These have their cell-walls thickened, 

 and there is a thick cuticle. Some of the epidermal cells contain tannin. 

 On the upper surface there are numerous glands which are formed from 

 epidermal cells. 



