delicate spines. From the center of each group arises a black slender hooked spine. The flower is a relatively large one of a dainty rose color.
Space does not allow further description and the remaining shrubby vegetation, including the Lycia and Celtis, must be passed with mere reference. Two weeks after the advent of the rains the ground is clothed with many richly colored and often fragrant annuals and small perennials. Some of the latter, as for example an Encelia and a Cassia, persist through the drought, a hardiness explained in part, at least, by the felt-like protective layers on the leaves. Among the less resistant, but rapidly growing herbs are the fragrant flowered Martynia, with its large, double-hooked pods, and a Tribulus, bearing rich yellow poppy-like flowers.
With such surroundings, rich in material and opportunity, what may be accomplished at the desert laboratory? Much of the taxonomic work of this region has been done; but, in the light of modern research, much remains to do. The structure and development of scarcely one of these desert forms is properly understood, and a wide field awaits the student in these directions, while the peculiar physiology of these plants has scarcely been touched upon. Physiological and anatomical-physiological studies of wide extent may here be carried on. It is to the honor of American science that an opportunity such as this has been afforded by the Carnegie Institution.
