562 Ti'ansactions. j 



xylem with conspicuous annular vessels. Round, the whole cylinder is a 

 well-marked pericycle, interrupted at each band of sclereachyma. 



The pith consists of — (1) a tissue of thick-walled cells, rich in starch, 

 evidently assisting in giving rigidity to the stem ; (2) the pith proper of 

 large polygonal cells, thin-walled, with few and very small intercellular spaces. 



6. Juncus maritimus, var. australiensis. 



Stem. 



Epidermis with cells of the ordinary type, though rather smaller, and 

 without stomata above the bands of sclerenchyma. The stomata are not 

 sunk in the epidermis, as in the case of Leptocarptis. In surface-view the 

 guard-cells are long and narrow, with very much thickened inner walls. 



Chlorenchyma consisting of bands 5-6 layers deep. There are numerous 

 small elHpsoidal chlorophyll grains. 



Sclerenchyma of narrow, much elongated cells, in narrow bands between 

 the bands of chlorenchyma. Each band is continued to join the sclerenchyma 

 on the outer side of the f.v. bundle immediately beneath. 



The f.v, bundles are numerous, and scattered through the pith in very 

 irregular circles. Each has a well-marked bundle-sheath. 



The pith is large, and consists of rounded, thin-walled cells, with inter- 

 cellular spaces of ordinary size. There are also larger lysigenic air-spaces 

 specially towards the outer part of the pith. The schizogenic spaces are 

 smaller than those of most rushes {e.g., in the characteristic stellate paren- 

 chyma of J. conglomeratus). 



7. Atriplex patula. 

 Leaf. 



Epidermis : The cuticle is not thick, and stomata are found on both 

 surfaces. They are not numerous, and have small guard-cells sUghtly 

 below the level of the other cells. Anthocyan is found in many of the cells. 

 The epidermal cells immediately above and below the midrid are smaller, 

 and have thicker division-walls than the rest of the epidermal cells. 

 Shrunken, dead hairs cover the epidermis. 



Mesophyll is formed of palisadic cells, 6-8 layers, with very small inter- 

 cellular spaces, and small rather scanty chlorophyll grains. Surrounding 

 the midrib is a large mass of colourless parenchymatous cells, polygonal 

 in outhne, though those towards the upper surafce are somewhat elongated. 

 They are thin-walled, with the exception of 2-3 layers adjacent to either 

 epidermis. 



The midrib is very prominent, and is composed of 4 conspicuous bundles, 

 embedded in a mass of thick- walled cells, and with sclerenchyma at their 

 outer limits. 



Stem. 



As the stem is of a rather anomalous structure, a short account of it may 

 be given here. Sections were cut and stained very successfully with saf- 

 franin and methyl blue. The saffranin picked out cortex, pith, and phloem, 

 while the wood took on an intense blue stain. In section, 4 primary and 

 4 secondary ridges appear. 



Epidermis : In T.S. the cells on the ridges appear smaller ; but in 

 surface - view they are longer and narrower than those in the grooves. 

 Stomata are confined to the grooves, and anthocyan is found only in the cells 

 of the ridges. 



