38 BOARD OF AGRICULTURE. [Pub. Doc. 



think that the same may be found to be true of the common 

 or European apple and the wild crab of the Mississippi 

 valley. Various crabs of the Soulard type, which I once 

 thought to constitute a distinct species, appear upon further 

 study to be hybrids. We will also recall that the hybrid 

 grapes which have so far proved most valuable are those 

 obtained by Rogers between the American Vitis Labrusca 

 and the European wine grape ; and that the attempts of Has- 

 kell and others to hybridize associated species of native 

 grapes have given, at best, only indifferent results. To 

 these good results from hybrids of fruit trees and vines I 

 shall revert presently. 



Another theoretical point, which is borne out by practice, 

 is the conclusion that, because of the great differences and 

 lack of affinity between parents, pronounced hybrid offspring 

 are unstable. This is one of the greatest difficulties in the 

 way of the summary production of new varieties by means 

 of hybridization. It would appear, also, that, because of the 

 unlikeness of parents, hybrid offspring must be exceedingly 

 variable ; but, as a matter of fact, in many instances the 

 parents are so pronouncedly different that the hybrids rep- 

 resent a distinct type by themselves, or else they approach 

 very nearly to the characters of one of the parents. There 

 are, to be sure, many instances of exceedingly variable hy- 

 brid offspring, but they are usually the offspring of variable 

 parents. In other words, variability in offspring appears to 

 follow rather as a result of variability in parents than as a 

 result of mere unlikeness of characters. But the instability 

 of hybrid offspring when propagated by seed is notorious. 

 Wallace writes tbat "the effect of occasional crosses often 

 results in a great amount of variation, but it also leads to 

 instability of character, and is therefore very little employed 

 in the production of fixed and well-marked races." I may 

 remark again that, because of the unequal and unknown 

 powers of the parents, we can never predict what characters 

 will appear in the hybrids. This fact was well expressed by 

 Lindley a half century ago, in the phrase, "Hybridizing is 

 a game of chance played between man and plants." 



Bearing these fundamental propositions in mind, let us 

 pursue the subject somewhat in detail. We shall find at the 



