i 4 7 
Tree (Ginkgo biloba , L.). 
appears to have been especially abundant in more northern 
latitudes, whence it may have gradually retreated to escape 
from unfavourable climatic conditions. 
It is sometimes stated that the more deeply-lobed leaves of 
the Maidenhair tree recall most vividly the ancient forms ; 
this statement, while in the main supported by palaeonto¬ 
logical evidence, must not be made without reserve. Leaves 
with an entire lamina are occasionally met with in Jurassic 
strata (PI. X, Fig. 54); both forms of leaf were represented, 
though on the whole the species with more numerous and 
narrower segments predominated. 
