Oliver. — On Sar codes sanguined , Torr . 307 
present very constant (if exceptional) characters which agree 
with those belonging to herbarium specimens collected at 
various periods. With a little care the different root-axes 
can be dissected away from one another. Fig. 41 shows a 
fairly young portion of one axis drawn under the simple 
microscope. It bears numerous short branches (rootlets) 
arranged in four or five longitudinal rows, thus differing from 
Monotropa , which bears its rootlets in two or three rows. 
There secondary roots, in time, elongate and bear, in the 
same way, numerous roots of the third degree. By this 
continued branching the characteristic, dense, interwoven mass 
is produced. The lateral roots (of whatever degree) are not 
produced at right- angles on the axis from which they arise, 
but always slope forwards ; the axis of a lateral root making 
an angle of about 45 0 with the region of its mother root in 
front of its insertion. These lateral roots, while still very 
young and not exceeding three or four millimetres in length, 
are already beset with little tubercles. These tubercles 
represent the origin of young rootlets. 
Everywhere the surface of the roots is of a deep brown 
colour, and under a strong lens it shows a certain roughness 
of texture not found on the roots of ordinary plants. The 
roughness in question is due to the fact that the roots of 
Sarcodes are everywhere invested in a close-fitting sheath of 
fungal mycelium. Further examination shows that the roots 
here, as in Monotropa , display in a marked degree the phe- 
nomenon of Mycorhiza. 
First as to the more intimate structure of these roots. They 
are usually relatively thick and fleshy. A transverse section 
reveals a central vascular cylinder surrounded by a broad 
parenchymatous cortex. If the diameter of any root be 2 mm., 
that of the vascular cylinder will not exceed -5 mm. The 
xylems, usually five in number, are arranged in a ring, alter- 
nating with softer regions, the phloems, in the manner charac- 
teristic of roots. In the younger regions there is a central 
pith, gradually however, becoming lignified and binding the 
individual xylems into one mass. The xylem consists of 
