MENDEL'S LAW. 269 



MENDEL'S LAW. 



BY W. J. SPILLMAN, 



U. S. DEPARTMENT OF AGRICULTURE. 



^VT"0 discovery in recent years has aroused more interest amongst 

 -^ biologists than that of Mendel's Law. If subsequent investiga- 

 tions confirm it as those thus far made have done it can not be consid- 

 ered less than epoch-making. Its importance to plant breeders seems 

 hardly less than that of the atomic theory to the science of chemistry. 

 Professor Bateson, of Cambridge, says there is reason to believe that 

 the plant breeder may eventually be able, by means of this law, to 

 produce a desired hybrid type with the same degree of accuracy as the 

 chemist now constructs a compound. It is impossible, on the thresh- 

 old of such a discovery, to state just how far-reaching its importance 

 is; we must wait for further investigation before hoping for too much. 



As the history of this discovery is not yet generally known, it 

 may be stated that Mendel 's original paper was published in an obscure 

 periodical at Briinn, Austria, in 1865.* This publication received 

 slight notice until De Vries, in March, 1900,f published an exact 

 counterpart of Mendel's theory, including some technical terms pro- 

 posed by Mendel, and gave some of the results of his own researches 

 to confirm the theory. Shortly after this, Correns of Germany and 

 Bateson of England published results of their own work, showing 

 that each of them had discovered the same law. Meanwhile the 

 writer, working on hybrid wheats in this country, announced the law 

 (but not the theory) in November, 1901. J The knowledge of this 

 discovery has become general only during the past few months. It 

 now remains for other investigators to apply it to their own results 

 for confirmation or modification. 



As the distinction between varieties and species can not always 

 be drawn with exactness, and particularly since Mendel's law applies 

 alike to crosses and hybrids, it seems justifiable, at least in a dis- 

 cussion such as the present one, to conform to the growing usage of 

 biologists in this country by using the term hybrid to include crosses 

 of all kinds, whether between varieties or distantly related species. 

 I shall, therefore, use the term hybrid in this sense. In the following 



* Verhandl. d. Naturf. Vereines, Briinn, 1865. 



t Compte Rendus, March 20, 1900. 



% Bui. 115, Off. Exper. Sta., U. S. Dept. Agric. 



