(420) 
physiology of the entire group although the mycorhizas, and 
the roots as well, of many of them were not observed. Ptero- 
spora was examined by MacDougal anatomically and observa- 
tions of its habits were made in the field during one season (5). 
A review of the various papers bearing upon the subject 
shows so many discrepancies of statement that it was deemed 
advisable to re-examine material of Prerospora, Sarcodes, 
fTypopitys and Monotropa, with a view to the determination 
of the comparative degeneration of the roots and the anatom- 
ical relations of the two symbionts. The material of Sar- 
codes was furnished by Dr. G. F. Peirce of Stanford Uni- 
versity, and includes young specimens taken at the beginning 
of the formation of the shoot, which do not show all the char- 
acters of Sarcodes sanguinea Torr., and possibly represent a 
new variety or an undescribed species of this genus. This 
may account in part for the disagreement of our results from 
those of Oliver (6). 
The shoots in this family are of course purely reproductive 
in their purpose, since all of the energy of the plant in the 
form of organic substances is taken in through the roots by 
the codperation of the sheathing fungus. As a consequence 
the ordinary 1elations of size and extension of the root and 
shoot systems disappear. 
Sarcodes exhibits a stem which may reach 35 cm. in height 
and 2 to § cm. in thickness, bearing numbers of fleshy scales 
and bracts liberally supplied with stalked glands. The root 
system is densely branched and the total bulk is greatly in 
excess of that of the aérial shoot, and also exceeds the bulk 
of the soil in the space occupied. 
Pierospora sends up a cylindrical stalk furnished with 
bracts and numerous glands reaching a height of 50 to 150 cm. 
and a diameter of .5 to r.1 cm. The root system is a small 
compact mass not more than two or three times the bulk of 
the basal section of the stem, and is totally inadequate to the 
mechanical fixation and support of the heavy aérial stalk. 
This stalk is, most anomalously, supplied with stomata. 
Monotropa and Hypopitys exhibit a heavy development of 
