Xll PKOCEEDINGS OF THE 



in the appreciation of affinity and diversity must be estimated, as 

 we do other characters, not a priori, but by their observed con- 

 stancy. 



Since the publication of Mr. Darwin's work, two important bo- 

 tanical papers on the subject have appeared, — ^the one the result of 

 ten years' experiments, carried on, perhaps, in some measure with 

 a view to proving a preconceived theory ; the other after eight years' 

 experiments, but on a larger scale, and apparently with less of 

 bias, and that in an opposite direction : the conclusions of the 

 one are in direct opposition to, — of the other, as far as they go, 

 confirmatory of, — Mr. Darwin's. Neither contains any reference to 

 Mr. Darwin's cliapter, which most probably the one author had 

 never seen, and the other had not had an opportunity of studying, 

 before drawing up his conclusions ; we may therefore consider both 

 these memoirs as founded on an independent study of previous 

 works, as well as on personal observations. 



The immediate occasion of the publication of both memoirs, 

 was the prize offered by the Academie des Sciences, in 1861, to be 

 awarded in 1862, "Etudier les Hybrides vegetaux an point de 

 vue de leur fecondite et de la perpetuite ou non-perpetuite de 

 leurs caracteres." As it was impossible that such a study could 

 be usefuUy completed in a single twelvemonth, the Academy, in 

 offering the prize, must have had specially in view one or both of 

 these observers, who were known to have been for years carrying 

 on experiments on the subject. 



Accordingly memoirs were sent in by M. Grodron, Dean of the 

 Eaculte des Sciences of Nancy, and one of the authors of an 

 elaborate and in many respects excellent 'Flore de France,' in 

 which more definiteness had been ascribed to hybrids than in al- 

 most any other work ; and by M. Naudiu, Aide-Naturaliste at the 

 Museum d'PIistoire NatureUe at the Jardin des Plantes, whose 

 attention had been probably first directed to the subject in the 

 course of his researches on Cucurbitacese. The former had carried 

 on his experiments in the Botanic Garden of Nancy, and had also 

 much studied the real or supposed wild hybrids of the centre and 

 south of France ; the latter had experimented, on a much larger 

 scale, on plots of ground allotted to him in the Jardin des Plantes, 

 where, moreover, he had the benefit of the gTeat experience and 

 judgment of his distinguished friend, M. Decaisne. 



M. Grodron' s memoir is printed at length in the ' Annales des 

 Sciences Naturelles ' (ser. 4, vol. xix. p. 135). He concludes, as he 

 began, with the conviction that mongrels or crosses between the 



