THE CACTUS 103 



Missouri, and Colorado, South America, north 

 and south Africa, and regions around the Medi- 

 terranean. It could not be known at the outset 

 just what crosses would be most effective, and 

 so experimented on every species on which I 

 could lay hands. I pollenized the giant Tunas 

 with pollen of the little trailing cactus, and with 

 such inconspicuous cousins of the giant as the 

 little hardy Opuntia vulgaris. 



There were several small more or less spine- 

 less species available, and others that produced 

 a comparatively small crop of spines, and of 

 course it was recognized from the outset that 

 these must be our main reliance. Just as the 

 little French partially stoneless plum had been 

 the foundation for building the stoneless plums 

 and prunes of to-day, it was thought that the 

 little cactus that was smooth-skinned might fur- 

 nish the element of spinelessness in all the future 

 races of spineless cactus, however varied the 

 other elements of their heritage. 



The most curious feature about the crossing 

 of the giant Opuntias with the small species, in 

 particular with the little cactus of the eastern 

 United States known as Opuntia vulgaris, was 

 that the hybrid was intermediate between the 

 parents as to every characteristic but one. In 

 size, stem, and manner of growth and form of 



