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W. A. CANNON 



ture was thoroughly moistened, and was left in the greenhouse 

 during the summer during which time it was occasionally given 

 water. On October 4 the plant was removed from the tube. 

 At that time a shoot 1 cm. long had been formed and both the 

 new and the older shoots were clothed with leaves. The root- 

 system of the specimen was found to consist of a slender main 

 root, 1.1 m. long, and of numerous laterals which were mostly 

 very short. Of the laterals, one took its origin from near the 

 crown of the main root and reached downward 30 cm. The 

 character of the roots of the plant is shown in figure 4, B. 



In the second culture seeds were sown in early spring in gal- 

 vanized iron tubes, 15. em. in diameter and about 1.5 m. in 

 length. The soil was equal parts adobe and sand. The cul- 

 tures were given water frequently until June 1, and occasionally 

 during the siunmer and autumn until they were taken down, 

 November 27. The root-system of one of the seedlings was found 

 to consist of a main root, which penetrated 47 cm., and of num- 

 erous short laterals which arose throughout its entire length. All 

 of the roots were fibrous. 



In brief, the results of the two lines of experiments indicate 

 that the roots of Fouquieria are really capable of deeper pene- 

 tration of the soil than has been found in natufe to be the case. 

 It is not improbable, further, that cultures of longer standing 

 might show still deeper penetration. Cultures are at the pres- 

 ent time running to test this point. 



Opuntia arbuscula 



Early in the spring of 1912 a section of the stem of Opuntia 

 arbuscula, whose root-system has already been described, was 

 removed from a specimen growing in the experimental plot and 

 set out in a glass tube 3 cm. in diameter and L40 m. long. The 

 soil of the tube was two parts adobe and one part sand. The 

 culture was placed on the east side of the lath shelter near the 

 experimental garden and was left until November 27. It was 

 given water by sub-irrigation until June 1, and but little after 

 that date. 



