34-0 BOTANY [Chap. XI 



Letter 664 I am glad that he is cautious about Naudin's view, 1 for I 

 cannot think that it will hold. The tendency of hybrids to 

 revert to either parent is part of a wider law (which I am 

 fully convinced that I can show experimentally), namely, that 

 crossing races as well as species tends to bring back characters 

 which existed in progenitors hundreds and thousands of 

 generations ago. Why this should be so, God knows. But 

 Naudin's view throws no light, that I can see, on this re- 

 version of long-lost characters. I wish the Ray Society 

 would translate Gartner's Bastarderzeugung 2 ; it contains 

 more valuable matter than all other writers put together, 

 and would do great service if better known. 



1 C. Naudin's " Nouvelles Recherches sur l'Hybridite dans les 



Vegetaux." The complete paper, with coloured plates, was presented to 



the Academy in 1861, and published in full in the Nouvelles Archives du 



Museum dHist. Nat., Vol. I., 1865, p. 25. The second part only appeared 



in the Ann. Sci. Nat., XIX., 1863. Mr. Bentham's address dealing with 



hybridism is in Proc. Linn. Soc, VIII., 1864, p. ix. A review of Naudin 



is given in the Natural History Review, 1864, p. 50. Naudin's paper is 



of much interest, as containing a mechanical theory of reproduction of 



the same general character as that of pangenesis. In the Variation of 



Animals and Plants, Ed. II., Vol. II., p. 395, Darwin states that in his 



treatment of hybridism in terms of gemmules he is practically following 



Naudin's treatment of the same theme in terms of "essences." Naudin, 



however, does not clearly distinguish between hybrid and pure gemmules, 



and makes the assumption that the hybrid or mixed essences tend 



constantly to dissociate into pure parental essences, and thus lead to 



reversion. It is to this view that Darwin refers when he says that 



Naudin's view throws no light on the reversion to long-lost characters. 



His own attempt at explaining this fact occurs in Variation under 



Domest., II., Ed. II., p. 595. Mr. Bateson {Mendel s Principle of Heredity, 



Cambridge, 1902, p. 38) says: "Naudin clearly enuntiated what we 



shall henceforth know as the Mendelian conception of the dissociation 



of characters of cross-breds in the formation of the germ-cells, though 



apparently he never developed this conception." It is remarkable that, 



as far as we know, Darwin never in any way came across Mendel's work. 



One of Darwin's correspondents, however, the late Mr. T. Laxton, of 



Stamford, was close on the trail of Mendelian principle. Mr. Bateson 



writes {op. cit., p. 181) : " Had he [Laxton] with his other gifts combined 



that penetration which detects a great principle hidden in the thin mist 



of ' exceptions,' we should have been able to claim for him that honour 



which must ever be Mendel's in the history of discovery." 



2 Versuche iiber die Bastarderzeugung im Pflanzenreich : Stuttgart, 

 1849. 



