No. 62S] VON GABTNER J. YD PLANT JIYBTIWIZATION 433 



lislimont of tlie theory, that all that was done by others would seem of 

 small iniporlanoe" (p. 427). 



As Focke says ((1) ]). 4:57). '■In iiunihers of experiments, he has 

 prol)ably Ixmmi surpassed l)y no otlier liybridizer." 



An idea of tlio sheer laborious work which Gartner's 

 operations involved, maybe obtained from the mere state- 

 ment that he performed close to ten thousand separate 

 experiments in crossing, involving nearly seven hundred 

 different species belonging to eighty different genera, and 

 from which some two hundred and fifty hybrid plants 

 were produced. 



From such a large mass of detail as Gartner's memoir 

 involves, it is difficult to derive a concise series of state- 

 ments of the experimental results. In endeavoring to 

 group the phenomena of hybridization upon a scientific 

 basis, Gartner undertook to classify hybrids into three 

 divisions, according to their external habit: (1) inter- 

 mediate types," (2) ''commingled types," and (3) 

 "decided types," although, as he says (p. 277) : 



There exists no oxaet deliinitalion among them, but they go variously 

 over into one another, so that il is not seldom very doubtful to which of 

 these forms, this ur llmt hybrid should, with the greater right be 

 assigned. 



In regard to the intermediate types, Gartner follows 

 Koelreuter's view 



that, as in the fertilization of pure species, so also with hybrid breeding 

 in the case of simple hybrids, a complete balance occurred of both fertil- 



he was still further strengthened through the similarity of types from 

 reciprocal crossing. He believed further, that in the later generations of 



such regular process of hybridization occurs, the inclination of types 

 either toward the father or the mother, proceeded from the not quite 

 complete balance, or the slight overbalance of the one or the other 

 fertilization materials (p. 277). 



Regarding the so-called ''commingled" types, Gartner 

 says as follows (p. 282) : 



