26 
LORQUINIA 
thickening of the epidermis, giving them a leathery texture. The 
CaHfornia Holly, Hctcromclcs arbutifolia, the needles of the conifers, 
Rhus laurina, Rhus ovata and others are examples of this method. 
Mountain mahogany, Cercocarpus hctulacf alius, has small leaves 
thickened and covered with fine hairs. The evergreen oaks all have 
thick, stiff leaves. The manzanitas have the majority of the leaves 
in a vertical plane to the smi's rays like the eucalyptus and also others. 
It is perhaps among the annuals, especially the very numerous 
Compositae, where we find the most common methods of protection. 
Corethrogync has the whole plant covered with a white covering of 
fine hairs as a protection. Grindclia cainporiiin has very thick or 
tough leaves and sticky glutinous heads. Deinandra fasciculatum has 
a resinous exudation to ward off the hot rays of the sun ; and 
Hcmizonia luzidacfoUa has the same. The Sun-flowers, Helianthus, 
have thick leaves covered with spiny or scale-like appendages. The 
Barberry, Bcrheris, a patch of which grows on Switzer's Trail in 
the San Gabriel Mountains, has excessively harsh spiny leaves. 
There are numerous instances and kinds of protection among our 
xerophilous plants which are interesting and worth recording. 
R GRINNELL, JR., 
Pasadena, Gal. 
OBSERVING THE FEEDING HABITS OF THE 
PACIFIC RATTLESNAKE 
Of a rather well balanced judgment and 'with a philosophic 
attitude toward captivity, the Pacific Rattlesnake (Crotalus oregonus, 
Holbrook) eats, drinks and makes the best of life as a captive in the 
terrarium of an herpetologist. As a general rule the Pacific Rattle- 
snake is far less excitable than some species of rattlesnakes, and. 
for this reason, is an excellent member of the family for one to 
observe with regard to the food he eats. 
In discovering what forms the food of any particular species of 
snake, the student has recourse to three methods. He may, by dis- 
section, examine the contents of the stomachs of a large series of 
dead snakes. In the field he may, by accident and diligence, stumble 
upon snakes in the act of devouring prey. By keeping in captivity 
