INFLUENCE OF ENVIRONMENT 273 
bay. The protective character of the strong odors 
found in many plants of the same regions has also been 
referred to. 
Where a region is subjected to well-marked wet and 
dry seasons, there are always a great many plants which 
pass the dry season in a dormant condition, very much 
as similar plants hibernate during the cold season of 
more northern regions. These plants generally develop 
bulbs or tubers, which may be completely dried up 
without injury. Bulbous plants are especially abun- 
dant in such semi-arid regions as central and southern 
California, the Cape of Good Hope, and the shores of 
the Mediterranean, where many bulbous Monocotyle- 
dons occur, among them some of the choicest garden 
flowers, like the various species of Narcissus, Iris, 
Gladiolus, ete. 
While these special adaptations to resisting dryness 
are particularly well developed in the flowering plants, 
there are also many striking examples among the lower 
plants, especially among Pteridophytes and Bryophytes. 
In California many ferns become completely dried up 
during the long rainless summer, but some of them, 
like the gold-back fern (Gymnogramme triangularis), 
on being placed in water will revive immediately, the 
dried-up leaves unfolding. and becoming fresh and 
green. The curious “resurrection plant,” from the 
southern part of the state, is one of the club-mosses 
(Selaginella lepidophylla), and this has the same power 
of rapid resuscitation. Many mosses and liverworts 
show the same thing, the whole plant drying up 
completely and reviving almost instantaneously on 
being moistened. Less commonly in these plants 
T 
