178 I ( TTTrn T^URBAVF 



The foUowin^ »ea«oa « few of tiic plan is hof 

 one or two fruiU hATing two or three drupcleU 

 mAt like mere f ragOMiiti of a normal raspheny. 

 But not a teed was found. The plants were ai 

 •ttrile at mules. So here the experunent endt ' 

 and the hyhrid strawberr>'-raspbeiTiM followed 

 the hybrid dr^wberries to the brush heap. 



Uhv the KxrEUHENTs Failsd 



If we now oonsider the results of these rarious 

 ezperiments, it will be elear that they havtt 

 oertain elements in common. In all cases the 

 hybridizing was effected between s})ccie8 that 

 are botanically related. But in no case was the 

 relationship between the mated fonns ver>' close. 

 And tills fact is of course of salient importance 

 in enabling us to comprehend the results. 



It is almost axiomatic to say that the hybrid- 

 ising of plants generally becomes increasingly 

 difficult in proportion as the attempt is made to 

 cross more and more distantly related species. 

 Kven within the same genus it is very often 

 impossible to produce a hybrid that is not 

 sterile. 



I might cite in further iliustration of these 

 difficulties the experiments through which I have 

 hybridized the apple with the pear, and with the 

 quince; the clierry with the plum; and the peach 



