CACTUS AND GREASE-WOOD 



135 



As an extra precaution some shrubs are given 

 a shellac-like sap or gum with which they var- 

 nish their leaves and make evaporation almost 

 impossible. The ordinary grease- wood is an ex- 

 ample of this ; and perhaps because of its var- 

 nish, it is, with the cacti, the hardiest of all the 

 desert growths. It is found wherever anything 

 living is found, and flourishes under the fiercest 

 heat. Its leaves always look bright and have a 

 sticky feeling about them as though recently 

 shellacked. 



There are other growths that seem to have a 

 fine sense of discretion in the matter of danger, 

 for they let fall all their leaves at the first ap- 

 proach of drouth. The ocatilla, or "candle 

 wood " as it is sometimes called, puts out a long 

 row of bright leaves along its stems after a rain, 

 but as soon as drouth comes it sheds them has- 

 tily and then stands for months in the sunlight 

 a bundle of bare sticks soaked with a resin 

 that will burn with fire, but will not evaporate 

 with heat. The sangre de dragon (sometimes 

 called sangre en grado) does the same thing. 



But Nature's most common device for the 

 protection and preservation of her desert brood 

 is to supply them with wonderful facilities for 

 finding and sapping what moisture there is, and 



Gums and 

 varnishes 

 of bushes. 



The ocatiUa. 



