57 



chance. Even to grow it experimentally required expensive 

 fencing to keep the gophers and jack rabbits away, as these 

 rodents would destroy any unprotected succulent. It is obvious, 

 therefore, that spineless cacti cannot be economically grown if 

 they must be protected by rabbit-proof fencing. 



Paradoxically, also. Professor Thornber found that the best 

 kinds of cactus for cattle food were the spiniest types of prickly 

 pear and cholla, simply because neither rabbit nor even a jack- 

 ass could eat them. The explanation of this apparently contra- 

 dictorv state of affairs is found in the fact that these spiny 



Spiny cacti as cattle forage. The picture shows a man operating a gasoline 

 singeing apparatus, to burn off the sharp spines, while cattle are following 

 along, and browsing from the treated plants. Courtesy of Dr. David Griffiths, 

 Bureau of Plant Industry. 



kinds can be made available for cow fodder by an inexpensive 

 process of singeing in which a specially constructed gasoline 

 torch is used to burn off the protective armature. They may 

 also be prepared by cutting off whole branches and then chop- 

 ping these up in cutting machines. It was a final conclusion of 

 the Thornber experiments that the cultivation of cacti for 

 cattle forage deserved extension and promotion, although by 

 itself, cactus material is an incomplete ration, and requires to 

 be fed in conjunction with supplementary foods. 



