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THE AMERICAN NATURALIST [Vol. XLVI 



of a cause, but gives no hint of that cause. It is not strange, 

 therefore, that the modern statement of this law should have 

 gravitated backward toward the fundamental cause underlying 

 the law. The more usual statement of it at the present time is 

 an inference from the facts observed, and may be stated as 

 follows: 



When an individual is heterozygous for a given character it produces 

 two kinds of gametes with reference to that character, one like those 

 of one of its parents and the other like those of the other parent. 



Mendel himself gives the corresponding statement of the law 

 of recombination ; that is, he states the inference about the kinds 

 of gametes a hybrid must produce, as inferred by the types of 

 the resulting progeny. 



The principle of segregation, closely approximated long prior 

 to Mendel both by Goss 19 and by Sageret, 20 was clearly enun- 

 ciated by Naudin, 21 but these writers did not formulate their 



19 " In the summer of 1820, I deprived some blossoms of the Prolific olue 

 of their stamens, and the next day applied the pollen of a dwarf Pea, and 

 of which impregnation I obtained three pods of seeds. In the following 

 spring, when these were opened, in order to sow the seed, I found, to my 

 surprise, that the colour of the Peas, instead of being a deep blue, like their 

 female parent was of a yellowish white, like the male. Towards the end 

 of the summer I was equally surprised to find that these white seeds had 

 produced some pods with all blue, some with all white, and many with both 

 blue and white Peas in the same pod. 



' ' Last spring, I separated all the blue Peas from the white, and sowed 

 each colour in separate rows; and I now find that the blue produce only 

 blue, while the white seeds yield some pods with all white, and some with 

 both blue and white Peas intermixed."— Goss, John, "On the Variation in 

 the Colour of Peas, occasioned by Cross Impregnation. " In a letter to the 

 Secretary. Eead October 15, 1822. Transactions of the Horticultural So- 

 ciety of London, Vol. 1S24, pp. 234-235. 



""'Ainsi done, en definitive il m'a paru qu'en general la ressemblance 

 de 1 'hybride h ses deux ascendans consistait, non dans une fusion intime des 

 divers caractfcrs propres a chacun d 'eux en particulier, mais bien plutot dans 

 une distribution, soit egale, soit inegale, de ces memes caracteres: je dis 

 egale ou inegale, parce qu'elle est bien loin d'etre la meme dans tous les 

 individus hybrides provenant d'un meme origine, et il y a entre eux, une 

 tres grande diversity "—Sageret, A., "Considerations sur la production des 

 hybrides, des variantes et des varietes, en general, et sur celles de la famille 

 des Cucurbitacees en particulier." Annates des sciences naturelles, Vol. 8, 

 1826, p. 302. 



