342 



POPULAR SCIENCE MONTHLY. 



Encelia. 



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. 



