446 Holm. — Bar tout a , Muehl. An Anatomical Study. 
deposits of starch were observed. In this pith are located about eight 
leptome-strands, which are not arranged so as to correspond radially with 
the peripheral leptome, and they all are separated from the hadrome by 
layers of parenchyma pertaining to the pith. 
A somewhat different structure is to be observed in the lowermost 
of the aerial internodes, a short distance above the one described in the 
preceding. The internode is obtusely quadrangular in cross-section, and 
stomata occur ; these are level with epidermis and surrounded by four 
cells (Fig. 21). The cortical parenchyma is here composed of only three 
strata, which contain chlorophyll, and the intercellular spaces are very wide. 
Endodermis is very thick-walled and porous, and surrounds a central cylinder 
of the same constituents as described above, and arranged in the same way. 
The mestome-parenchyma is, however, more thick-walled than observed in 
the subterranean internodes, and the mestome represents now about eight 
distinct bicollateral mestome-strands, instead of a confluent mass of 
hadrome and isolated leptome, the innermost groups of which border here 
almost directly on the hadrome. The pith shows the same structure as 
above, but extends now between the hadrome to the protective sheath. 
This same structure was observed in all the other internodes above, but 
the cross-section becomes gradually more sharply quadrangular, and at the 
same time the number of peripheral leptome-strands becomes reduced to 
only four outside the several groups of hadrome with leptome on the 
inner side. 
I11 the peduncles of the flowers we noticed a corresponding structure, 
and chlorophyll was observed in the guard-cells of the stomata and in the 
cortex. The peduncle is sharply quadrangular, and contains a thin-walled 
endodermis, surrounding a central cylinder with four broad strands of 
leptome corresponding with the four angles, besides a sheath of thick- 
walled mestome-parenchyma as above. The hadrome forms an almost 
closed ring with about five internal strands of leptome, and a central, thin- 
walled pith without starch. 
The Leaf. 
The leaves are of the same shape and small size as those of B . verna , 
and possess the same kind of glandular hairs as observed in this species. 
A transverse section of the leaf (Plate XXXIII, Fig. 16) shows a smooth cuti- 
cle and a moderate thickening of the outer cell-walls of epidermis. Stomata 
level with epidermis occur on both faces of the blade. The chlorenchyma 
constitutes a homogeneous tissue of roundish cells, which contain chloro- 
phyll ; the intercellular spaces are narrow, and no lacunes were observed. 
No stereome is developed, and the single mediane vein possesses no paren- 
chyma-sheath, but only a very few leptome-cells and narrow vessels. The 
leaf-structure is thus almost identical with that of B. verna . 
