Roberts: The Founders of the Art of Breeding 231 



ture of certain parts, now approximating 

 more to the father, now to the mother" 

 (p. 25). 



Wiegmann's independence of tradi- 

 tional authority is witnessed in his con- 

 tradiction of the view of "the great 

 Linnaeus," that hybrids resemble the 

 mother in the fertilization apparatus 

 and the father in foliage and habit. 

 Instead, he says: "the change through 

 the foreign fertilizing pollen shows 

 itself in very different parts in dif- 

 erent plants; in the anther filam- 

 ents, ... in the inflorescence, in 

 the form, color, and odor of the corolla, 

 in the height of the stem and its divi- 

 sions, in the form and outside covering 

 of the leaf" (p. 23). 



Referring to tlie then general assump- 

 tion that hybrids (of the Fi generation, 

 as we should say) occupy a mid-position, 

 with respect to their characters, between 

 the two parents, he says: ". . . in 

 many cases this does not occur, but 

 either the color of the father or that of 

 the mother shows itself alone dominant 

 (herrshend) in the hybrid. The same 

 also obtains among animal hybrids; 

 the two colors may, through mingling, 

 give an intermediate one, but in just as 

 many cases the one only prevails. 

 Plant hybrids therefore unite in them- 

 selves in part the peculiarities of the 

 father, in part those of the mother, 

 whereby they approach now the mater- 

 nal, now the paternal form" (p. 21). 



THE QUESTION OF DOMINANCE 



Regarding the matter of dominance, 

 Wiegmann further incidentally remarks 

 upon the case of the crossing of two 

 species of Dianthus, where "the form 

 of the father has almost entirely sup- 

 pressed that of the mother" (p. 22). 



To present-day geneticists, one of 

 the most interesting points in Wieg- 

 mann's report is his discussion of the 

 immediate effect of the pollen in the 

 case of peas. According to his state- 

 ment, that there occurs, "even imme- 

 diately after fertilization, an alteration 

 arising in the form and color of the seed, 

 and in the form and size of the pods, is 

 especially unmistakable in the case 

 of the leguminous plants, although 



otherwise all fruits and seeds of hybrid 

 plants from other families, have never 

 shown themselves to me to be different 

 from those of the mother plants" (p. 

 23). And again, "The principle ex- 

 pressed by Gartner, that the influence 

 of foreign pollen changes nothing in the 

 form and external character of the fruits 

 and seeds of the mother plant, should, 

 according to my investigations, undergo 

 a modification in the case of the Dia- 

 delphia (Leguminosae), since, in the 

 case of these, the foreign pollen exerts 

 an immediate effect upon the form, color, 

 and other characters of the fruits and 

 seeds" (p. 29). 



In the case of Phaseolus (common 

 bean), he says; "Previous experiments 

 have taught me that Phaseoli of one 

 species, but of two kinds of flowers and 

 seeds, when placed together, bear differ- 

 entl}^ colored seeds, and, in the second 

 generation, also differently colored flow- 

 ers" (p. 23). 



Wiegmann carried on some field ex- 

 periments with beans, vetches, oats, 

 and cabbage, in which adjoining rows 

 of plants were allowed to freely cross- 

 pollinate through the agency of wind and 

 insects, from which he concluded: "It 

 appears further, from the behavior of 

 the Leguminosae and of cabbage, that 

 agronomists and gardeners cannot be 

 careful enough in the arrangement of 

 their fields, in order not to suffer from 

 the great damage through hybrid fer- 

 tilization occurring even the first vear" 

 (p. 36). 



Speaking generally, he says further 

 (p. 30): "It is not entirely improbable 

 that that which exhibited itself to me 

 thus far, as being peculiar to the 

 Leguminosae alone, may take place 

 also among other plant-families, and 

 the clearing up of this matter remains 

 very desirable for botany, as well as for 

 agriculture in particular" (p. 30). 



Wiegmann's work, as a whole, im- 

 presses one astheworkof a man without 

 scientific prepossessions, willing to in- 

 vestigate for himself, to dispute freely 

 the authority of other investigators 

 such as Linnaeus, Koelreuter. and Gart- 

 ner, and, withal, a man with a prac- 

 tical bias and a sympathy for agriculture. 



