326 



The Journal of Heredity 



V 



1^1 



IIVUKIDS AKE NOTED FOR VIGOR 



The center row in this photograph is a collection of ordinary commercial varieties of straw- 

 berry; while on either side are rows of hylirids produced by Albert F. Etter. Tt is well 

 known that, in general, hyljridization tends to increase the vigor of plants and animals, 

 and this fact is often turned to advantage in modern breeding. It is evident that the Etters- 

 burg strawberries are much more vigorous growers than common commercial varieties 

 which, although originally hybrids, have been propagated so long that they have lost most 

 of the benefit accruing to them from their original hybridization. (Fig. 17.) 



an indication of the extreme variability 

 which consequently might be expected 

 in the hybrids. 



The two other species which have 

 been used extensively in the hybrids 

 thus far j^roduced are F. vesca semper- 

 jlorens, the Alpines, and F. californica, 

 the native wood strawberry. Stock of 

 the former was obtained by growing 

 seedlings from seed suj^jjlied by John 

 Lewis Childs of Floral Park, New York. 

 Some of these seedlings bore red and 

 others white berries, and some of the 

 plants produced runners and others did 

 not, as is characteristic of the Al])inc 

 strawberries. All of these forms were 

 used in the hybridization work. The 

 wood strawberry used was derived from 

 local sources and displayed the char- 



acteristics usual for that species, namely 

 free production of very small inferior 

 berries and a tendency towards winter 

 growing. These three represent all the 

 mid sjjccies concerned in the hybrids 

 considered in this article. Others are 

 now being used, among them F. 

 cunci folia, a distinct and somewhat 

 peculiar type from Oregon, and F. 

 chincnsis \'arietics originally deri\'od 

 from Chinese sources. 



G.\RDEN VARIETIES USED 



As a foundation for the work a 

 number of common garden varieties 

 which have met with some favor in 

 California have l)een used. Among 

 these are the Sharjjlcss and Parry, 

 ])reviously mentioned, and of Iheotliers, 



