336 



W. A. CANNON 



When the experiment was terminated the shoot consisted of 

 two branches of which one was 33 cm. and the other 47 cm. 

 long. The roots of the plant were composed of a fleshy main 

 root that ran to the end of the tube, that is, 43 cm. Aborted 

 laterals were numerous along the fleshy root, and two laterals, 

 which took their origin near the root crown, extended nearly 

 to the end of the tube. These were fibrous. At the lower end 

 of the tube (See fig. 4, A) the main root broke up into several 

 slender branches, and two of these, which were longer than the 

 rest, after leaving the tube, inclined sharply upward and finally 

 attained a level within 4 cm. of the surface of the ground outside 

 the tube. These roots again branched, and, like them, the ulti- 

 mate branches were fibrous. 



Fouquieria splendens 



Fouquieria splendens is a spinose perennial whose interest in 

 the present connection, as aheady indicated, lies in the fact that 

 its root-system is in a measure intermediate between the gen- 

 eralized type, as in Franseria dumosa, and the superficial type 

 of the cacti. The roots and the shoots also are somewhat fleshy 

 and serve as reservoirs for food and water. The following sketch 

 of the roots of the species is of a plant growing on Tumamoc 

 Hill. The shoots were 1.75 m., or less, in length. The root- 

 system consisted of a stout main root, which was traced down- 

 ward 15 cm. Five laterals, also stout, arose near the crown of 

 the tap root. The roots inclined somewhat as they departed 

 from the central axis until they lay 16 to 37.5 cm. beneath the 

 surface of the ground. 



To learn to what depth the roots of Fouquieria would pene- 

 trate if the conditions were suitable, two kinds of experiments 

 were set up. Long glass tubes were used in one of these, as in 

 the Jatropha culture, and in the other, especially constructed 

 metal pipes, larger than the tubes and also of a greater diameter. 



Early in May, 1912, a young Fouquieria plant was brought 

 from its habitat on Tumamoc Hill into the greenhouse and placed 

 in a glass tube 3.5 cm. in diameter and 1.75 m. long. The cul- 



