PROCHEDINGS 
OF THE 
WASHINGTON ACADEMY OF SCIENCES 
VoL. X, PP. I-50. Puates J-II. JANUARY 18, 1908. 
STUDIES IN THE PHYSIOLOGY AND MORPHOL- 
OGY OF SOME CALIFORNIA HEPATIC. 
By Harry B. Humpurey, B.S. 
AcTING INSTRUCTOR IN BOTANY, LELAND STANFORD JUNIOR UNIVERSITY. 
THE morphology and physiology of the Hepatice have been 
treated by many authors, but their work has been confined mainly 
to the group as a whole. The intimate relations of the liver- 
worts to their environments, have however, received only inci- 
dental treatment. Ordinarily we are inclined to associate with 
the Hepaticze an environment characterized by moisture and 
shade. To a certain extent we are justified in doing so, for 
the majority of the known species occur in just such a habitat, 
many of the larger and more striking ones, such as Monoclea, 
Dumortiera and some species of Aneura, being common in the 
more humid regions of the tropics. On the other hand many 
species are known to occur normally in parts of the world where 
climatic conditions are not so evenly balanced as in the tropics ; 
many thrive in extreme northern and southern regions where 
they are subject to great variations in temperature, while those 
growing in regions like the west coast of the United States 
must adapt themselves to prolonged periods of drought alter- 
nating with six or seven months of rainy weather. 
It was with a view of ascertaining the nature and influence 
of these various conditions common to certain California hepat- 
icz that the present study was undertaken. 
Proc. Wash. Acad. Sci., January, 1908. I 
