THE STRUCTURE AND DEVELOPMENT OF CRYPIO 
MITRIUM TENERUM. 
LE Roy ABRAMS. 
(WITH SIX FIGURES) 
THE genus Cryptomitrium, represented by the single specie 
C. tenerum (Hook.) Austin, has not yet been thoroughly studied, 
and as the plant has been collected in several localities m# 
Stanford University,.at the suggestion of Dr. Campbell a stud} 
of its structure and development was undertaken, in order, 
possible, to determine its relationship to the other Marchantiaceé | 
The first collections were made late in the spring of 1898 
at which time the plants were mature, and the spores alos 
ripe. Some of these plants were placed in alcohol, whi 
others were allowed to become dry, and the earth upon ™ 
they were growing was kept until the following Sept agi: 
when the work upon the plant was taken up. A consid 
number of the mature sporogonial receptacles were also put ¥ 
dry, inorder to study the germination of the spores. 
Some of the pieces of earth with the dried specimens 
them were thoroughly soaked, and then kept well m i 
Within a day or two the tips of the apparently dried-Up 
became green and fresh, and in about two weeks the am 
began to form. All of the material for study was © 
in this way, until after the rains came. Then comsit 
material was collected from out of doors, where it d 
much faster and was healthier than that grown in the 
atory. 
0 
THE THALLUS. . 
Cryptomitrium, like most other Marchantiace®, * 
dichotomously branched thallus, which in this spect 
thin and delicate. The smooth glossy appearance, P. 
one can easily distinguish the sterile plants from * 
IIo 
