Manchester Memoirs, Vol. hi. (191 1 -12). 



INAUGURAL ADDRESS. 



Researches on Heredity in Plants. 



By The President, 



Professor F. E. Weiss, D.Sc, F.L.S. 



October ^rd, igii. 



Ever since the discovery by Sprengel of the cross 

 fertilisation of flowers by insects, efforts v/ere made by 

 various experimenters to ascertain whether the pollen of 

 one species could fertilise the ovule of a different species, 

 whether in fact the characters of two distinct species could 

 be combined in a hybrid organism. Kcelreuter, Knight 

 and Gaertner w^ere among the first to make definite 

 experiments in this direction, and a general summary 

 of the very considerable amount of work done during 

 about 120 years was compiled and published by Focke in 

 1 88 1. With two brilliant exceptions, however, hardly 

 any of the investigators were able to formulate definite 

 laws governing the production of hybrids and the in- 

 heritance of parental characters, and Focke's encyclopaedic 

 work unfortunately laid no stress on the important 

 generalisations of Naudin and of Mendel. 



The earlier experimenters had concluded that hybrids 

 between different species exhibited some characters of 

 both parents, and Macfarlane, in his comparison of the 

 minute structure of plant hybrids, published in 1891, 

 laid it down as fundamental that the hybrid represented 

 an organism exactly intermediate in all its characters 

 between those of its two parents. This generalisation was, 

 however, based on the examination of a somewhat limited 



April 22nd, igi2. 



