114 
J. C. Th. Uphof. 
The writer regrets he was unable to study any of the plants 
of this group under natural conditions. The habitats of these 
plants, which differ widely from those of the other two groups, 
must have an effect on their development and behaviour, and these 
facts can only be satisfactorily studied in their native environment. 
Fig. VI. Selaginella sanguinolenta. 1, section of leafy stem ; 2, section of old 
leafless stem ; 3, section of leaf. Selaginella saccharata ; 4, 5, sections cf leaf. 
Group III. 
Plants of the last group are exceedingly well fitted for a 
semi-arid environment. The stems are densely tufted, and 
curl up into a more or less close cluster; the leaves are situated 
horizontally on both sides of the stem ; the dorsal leaves are only 
a little smaller than the ventral ones. The under sides of the ventral 
leaves, which become the outside of the cluster when curled up during 
drought, reflect much of the light they receive. The cells contain a 
large amount of oil. They form the series Rosulatas of Baker (1). 
The writer was able to study plants in their natural state, 
especially «$. lepidophylla in Southern California (environs of San 
Diego), and Northern Sonora, Mexico (a few miles from Los 
Nogales); 5. pilifera also was studied near Los Nogales. 
