2o8 THE PLANT WORLD 



is SO different that the former plant remains a single-stemmed 

 shrub of tree like habit, while the mariola has a bushy habit. 

 This marked difference, it will be seen, precludes the advis- 

 ability, though the possibility might remain, of grafting 

 the guayule on the mariola, a suggestion which has been 

 made on the assumption that increased growth might follow 

 in the scion. No economic result would follow and for this 

 reason. Supposing that we graft successfully a piece of 

 guayule on a stock of mariola. The scion grows, but at the 

 same time new shoots arise from the base of the stock as 

 described, and their growth is so rapid that in a month or two 

 the guayule shoot is o\'ertopped and this ends the usefulness 

 of the graft for economic purposes. We might \'ery well 

 make a graft for the purposes of pure science, but economic- 

 ally it would be a failure. 



An important question mav be asked with regard to the 

 relati\'e importance of the habits in these two plants in com- 

 petition, but any discussion at this point would be little better 

 than speculation, which, though interesting in itself would, 

 I fear, lead us beycMitl obser\-ed facts. 



HI-. Wl'Sri'RX KDGK OF 'mK COLORADO 



DESERT. 



By y. M. S P. \ I, DING. 



I he great desert region of the southwestern L^nited 

 States, which tra\"ellers b\' the Southern Pacific Railroad re- 

 member as a weary stretch from central Texas to the moun- 

 tains of California, though possessing certain general features 

 characteristic of arid or semi-arid regions the world over, 

 ne\ertheless exhibits a great yariety of climate, soil, and to- 

 pography, \Aith a corresponding \-ariety of plant life. In 

 the extreme western part of this area, in Ayhich the Salton 

 Basin is located, ami ^yhich is commonK' designated as the 



