480 Plant Physiology 



with alternative inheritance in hybrids, that is, with 

 offspring from parentage showing contrasting characters. 

 The work has resulted from a clear appreciation of certain 

 fundamental observations. A single case may serve to 

 typify the simplest form of the problem : Bearded wheat 

 is crossed with beardless. Will the progeny be bearded, 

 beardless, or intermediate ? What will hapJ3en in succeed- 

 ing generations? For the development of this line of 

 inquiry, we are indebted first of all to Gregor Johann 

 Mendel, - - Priest and later Pralat of the Konigskloster 

 of Brunn - - and to De Vries, Bateson, Castle, Correns, 

 Tschermak, and many others. Mendel's important con- 

 tribution was published in 1866, but it attracted no atten- 

 tion and was practically lost to the scientific world until 

 rediscovered in 1900. 1 



294. Mendel's experiments. - - Mendel had followed 

 carefully the work of such predecessors in this line of in- 

 vestigation as Kolreuter, Knight, Gartner, and others. 

 He was particularly interested in what has been charac- 

 terized as the constant appearance of the same hybrid forms 

 when any two species are crossed. He sought to deter- 

 mine the number of such forms which may arise, the con- 

 duct of these in the succeeding generations, and the rela- 

 tions of the forms one to another from a numerical or 

 statistical point of view. He had an unusually clear idea 

 of the indications which should be possessed by the species 

 employed in crossing in order to demonstrate the points 

 in a definite manner. He declared that species to be 



1 For a comprehensive, bibliographical sketch of Mendel, the student 

 should read the notice of him in Bateson's " Mendc4's Principles of Hered- 

 ity," pp. 304-316. 



