Roberts: The Founders of the Art of Breeding 



233 



Gartner undertook to classify hy- 

 brids for convenience into three types: 

 (1) intermediate, (2) commingled, and 

 (3) decided. The first included those 

 in which "a complete balance occurred 

 of both fertilizing materials, either in 

 respect to mass or activity" (p. 227). 

 Commingled types are those in which 

 "now this, now that part of the hybrid 

 approaches more to the maternal or to 

 the paternal form, whereby, however, 

 the characters of the parents, in their 

 transference to the new organism, never 

 go over pure, but in which the parental 

 characters always suffer a certain modi- 

 fication" (p. 282). Under the third 

 class of hybrids, Gartner places those 

 ' ' among which the resemblance of a hy- 

 brid to one of its parents, either to the 

 father or the mother, is so marked and 

 preponderating that the agreement with 

 the one or with the other is unques- 

 tioned" (p. 285). 



Gartner recognized, as did the other 

 hybridizers of his day, that there was 

 always a difference between the first 

 and the succeeding generations, the 

 former being uniform, the later ones 

 variously splitting up. He made no 

 distinction between the second and the 

 other following generations, and simply 

 says that the fundamental ground ma- 

 terial of which the hybrid is made ' ' be- 

 haves differently in the second and in 

 the further stages of breeding, where, 

 on account of the different nature of the 

 two factors of the hybrid in the suc- 

 ceeding fertilizations, an altered, shift- 

 ing, variable direction in type-forma- 

 tion enters into the arising varieties" (p. 

 572). 



He further says, concerning varia- 

 bility in hybrids of the second and suc- 

 ceeding generations: "Other hybrids, 

 and in fact the most of them which are 

 fertile, present from the seeds of the 

 second and further generations, dif- 

 ferent forms, i. e., varieties, varying 

 from the normal types, which in part 

 are unlike the original hybrid mother, 

 or deviate from the same, now more, 

 now less" (p. 422). 



Gartner's most definite statement, 

 however, regarding what we call "seg- 



regation" in the second hybrid gener- 

 ation, is as follows: "Among many fer- 

 tile hybrids, this change in the second 

 and succeeding generations affects not 

 only the flowers but also the entire 

 habit, even to the exclusion of the flow- 

 ers, whereby the majority of the indi- 

 viduals from a single cross ordinarily 

 retain the form of the hybrid mother, a 

 few others have become more like the 

 original mother parent, and, finally, 

 here and there an individual more 

 nearlv reverted to the original father" 

 (p. 422). 



Gartner did not fail to recognize the 

 fact of unusual vigor in hybrids, al- 

 though he does not distinguish as to the 

 generation: "The marked increase in 

 the size of the flowers is a phenomenon 

 not seldom occurring among hybrids" 

 (p. 295); and "one of the most marked 

 and general characters of plant hybrids 

 is the luxuriance of all their parts, since, 

 among very many of them, an exuber- 

 ance of growth and development of 

 roots, branches, leaves and flowers mani- 

 fests itself, which is not encountered 

 among the parents, even under careful 

 cultivating" (p. 526). 



PRACTICAL POSSIBILITIES 



Gartner recognized at once the pos- 

 sibilities for agriculture in this fact of 

 the increased vigor of hybrids, although, 

 of course, he did not realize the fact that 

 this increased vigor belonged to the first 

 or hybrid generation, properly so called: 

 "Among the characters of hybrids 

 worthy of recommendation for agricul- 

 ture, their tendency toward luxuriance 

 in stalks and leaves and their extra- 

 ordinary capacity for tillering is 

 related above. With respect to the rais- 

 ing of forage, agriculture could, without 

 doubt, make great use of this charac- 

 teristic" (p. 634). 



Gartner derived, from his long ex- 

 perience, a certain philosophy concern- 

 ing the nature of hybrids which is note- 

 worthy. He recognized an inequality 

 in the influences or the "potency," as 

 he termed it, of one parent over another 

 in a cross, which potency was m.ain- 

 tained, whichever way the cross was 

 made. As we now understand it, it 



