INTERNATIONAL CONFERENCE ON PLANT BREEDING. 417 



NOTES ON THE " PROCEEDINGS OF THE INTERNATIONAL 

 CONFERENCE ON PLANT ; BREEDING AND HYBRIDISA- 

 TION, 1902." 



By C. C. Hurst, F.L.S. 



The first International Conference on Hybridisation was held in London 

 in 1899 under the auspices of the Royal Horticultural Society, a full 

 report of which was published in this Journal, vol. xxiv. (1900), 

 pp. 1-348. 



The second International Conference was held in New York in 1902 

 under the auspices of the Horticultural Society of New York, a full report 

 of which has recently been published in the " Memoirs " of that Society, 

 vol. i. (1904), pp. 1-271. 



A third International Conference is announced to be held at the Royal 

 Horticultural Society's new buildings in Vincent Square, Westminster, 

 commencing on Tuesday, July 31, 1906. All who are interested in the 

 subject should at once send in their names to the Secretary of the 

 Society, who will in due course send them the different notices and 

 programme as published. 



In the following notes an attempt is made to review the leading 

 features of the American report. 



As a result of the recent discoveries in heredity by Mendel and his 

 successors, the whole question of hybridisation has taken on a new phase, 

 and in these circumstances it is hardly surprising to find that the key- 

 note of the American Conference was the possibility of applying the 

 Mendelian principles to economic plant breeding. 



Mr. Bateson opened the proceedings of the Conference by giving an 

 outline of the Mendelian principles of heredity, and the possibility of 

 their application to practical breeding. 



Practical Aspects of the New Discoveries in Heredity. 

 By W. Bateson, F.R.S., of England. 



This paper gives a brief account of the advances that have been made 

 since the re-discovery of Mendel's paper by de Vries in 1900. The all- 

 important discovery of the purity of the germ-cells in regard to each unit- 

 character is duly emphasised. The significance of this fact to the 

 practical breeder is shown to bo very great, as it revolutionises previous 

 conceptions as to the nature of artificial selection. In the author's own 

 words : " We have lost for ever, I think, the conception that fixity of 

 character is solely or chiefly a function of the number of generations 

 during which that character has been manifested, or of the number of 

 successive selections of that particular variety which has been made. 



" Purity of strain, or fixity of character, is, on the contrary, due 

 primarily to the union of similar gametes in fertilisation. Such purity 

 may therefore occur among the immediate offspring of cross-bred 

 organisms." It appears, therefore, that certain recessive characters, like 



