340 Plant Life and Evolution 



quite unlike either of the parents. The latter hy- 

 brid Burbank considers to be a case of reversion, 

 but this, however, may be questioned. 



Thus we see that as the result of crossing be- 

 tween markedly different forms, quite new types of 

 flowers and fruits have been developed. Many arti- 

 ficial hybrids of orchids have resulted from cross- 

 ing widely separate species, or even genera, and 

 many of the novelties offered from time to time by 

 the florists are hybrids, sometimes combining char- 

 acters derived from several species. An example of 

 one of these compound hybrids is the Shasta daisy, 

 which is one of Burbank's " creations." The 

 " Plum-cot " is a cross between the plum and apricot, 

 and the Loganberry, now one of the standard fruits 

 of California, resulted from crossing a native black- 

 berry with the red raspberry. Among the most 

 interesting of the recent hybrid fruits are Webber's 

 Citrus-hybrids. Among these is the " Citrange," 

 a hybrid between the hardy Japanese Citrus trifoli- 

 ata and the sweet orange, which it is hoped may 

 prove the beginning of a race of hardy sweet 

 oranges. Another interesting hybrid is the " Tan- 

 gelo," a cross between the grape-fruit or pomelo, 

 and the Tangerine orange. 



The plant-breeder takes advantage of the insta- 

 bility produced by changed environment, but since 

 the time of Kolreuter's early experiments in hybrid- 

 ization, the great importance of crossing different 

 forms to induce variability has been clearly recog- 



