ON USEFUL SUBSTANCES IN CACTUS 



opuntias are somewhat lacking in protein content. 

 Their forage value is not quite what it would be 

 if the protein content could be increased. And 

 there is no reason to doubt that such increase may 

 be possible, through selective breeding. Already 

 the developed spineless opuntias exceed all other 

 plants in their capacity to produce an enormous 

 quantity of forage. Through selective breeding 

 their pre-eminence may be still further advanced 

 in that each individual slab may be given enhanced 

 food value. And the quantities of other useful 

 chemical substances in the cactus may similarly 

 be increased in selective varieties. 



Heretofore the develop- 

 ment of my cactus has been 

 along the lines of spineless- 

 ness, size and productivity; 

 the future will see a marked 

 improvement in the percent- 

 age of its food constituents. 



