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THE AMERICAN NATURALIST [Vol. XLVI 



also seem to have come very near to the discovery of Mendel's 

 principles. 



III. The Law of Kecombination 27 

 This law is based upon the following Mendelian principle 



("Versuche," etc., p. 22) : 

 Die Nachkommen der Hybriden, in welchen mehrere wesentlieh ver- 



schiedene Merkmale vereinigt sind, stellen die Glieder einer Combina- 



tionsreihe vor, in welchen die Entwicklungsreihen fiir je zwei differi- 



rende Merkmale verbunden sind. 



This principle may be thus translated: 



The progeny of hybrids, in which several essentially different char- 

 acters are combined represent the terms of a series of combinations, in 

 which the development series for each pair of differentiating characters 

 are united. 



Spillman in his recent paper entitled "The Application of 

 Some of the Principles of Heredity to Plant Breeding," 28 thus 

 concisely states this law : 



In the second generation of a hybrid there tends to occur every pos- 

 sible combination of the original parent characters. 



This law was also discovered by Spillman independently in 

 1901 and announced provisionally by him in a paper read before 

 the Association of American Agricultural College and Experi- 

 ment Stations in November of that year. 29 



The clearest and most comprehensive account of Mendel's work 

 extant is probably that of Bateson 30 in which may be found a 

 full discussion of the doctrine of Mendelism together with a 

 translation in English of Mendel's original papers. The French 



M Godron, D. A., "De l'espece et des races dans les etres organises," 

 2d ed., Vol. 1, Paris, 1872, pp. 180-266. 



"Vilmorin, H., "Note sur une experience relative a 1 'elude de* 1 'heredity 

 dans les vegetans," Paris, 1879, pp. 1-11. Extrait des memoires de la 

 society nationale d 'agriculture de France— Annee 1877. 



""Gesetz der Selbstlindigkeit der Merkmale," Correns, I. c, p. 208. 



"Bulletin No. 165, Bureau of Plant Industry, U. 8. Dept. Agriculture, 

 1909, p. 22. 



a Bulletin No. 115, Office of Experiment Stations, U. S. Dept. Agri- 

 culture, 1902, p. 88. 



"Bateson, W., "Mendel's Principles of Heredity," Cambridge, 1909. 



