THE CACTUS 167 



at Santa Rosa, although remaining perfectly 

 smooth under ordinary conditions of cultivation, 

 had, nevertheless, a tendency to revert to the 

 spiny condition if placed under disadvantageous 

 conditions say in arid soils, unwatered and un- 

 cultivated ; a state comparable to that of the wild 

 spiny progenitors. 



This tendency to reversion is in itself highly 

 interesting from the standpoint of the student of 

 heredity; being comparable, perhaps, to the 

 observed tendency of some plants, on rare occa- 

 sions, to form what are termed bud sports. As 

 a rule, plants grown from cuttings or roots or 

 buds reproduce absolutely the characteristics of 

 the parent form. We have seen this illustrated 

 over and over in endless numbers of cases, from 

 orchard fruits to Shasta daisies. This rule holds 

 true of the cactus, as has been pointed out in re- 

 cent chapters. You may produce an entire field 

 of spineless opuntias of any given type, as off- 

 shoots of a single slab. 



But of course no plant is free from the power 

 of environment, and no one needs to be told 

 that the choicest orchard fruits, for example, 

 will fail signally to justify expectations based 

 on observations of their parent forms, unless 

 they are given proper conditions of soil and cul- 

 tivation. Cuttings or buds of the Baldwin 



