30 THE MENDEL JOURNAL 



supreme value iu recent years, but it is difficiilt 

 even at the present day to fully realise the far- 

 reaching influence of a thorough appreciation of 

 the Law and of the facts brought to light in 

 connection with its establishment and verification. 

 There are, however, two important fields in which 

 they have had very striking consequences, and 

 a few words on these may fittingly serve as a 

 conclusion to this little sketch. 



Let us take first the effect which a know- 

 leds'e of Mendel's Law and the associated 

 facts have had upon the subject of variation in 

 animals and plants. It is apparent at once that 

 the fact that certain proportions of the progeny 

 of hybrids can be perfectly constant, although 

 exhibiting quite new combinations of characters 

 as compared with the original parents, gives the 

 clue to one important section of the very various 

 kinds of phenomena grouped under the general 

 term of variation. For instance, seven pairs of 

 characters can be combined theoretically in 

 one hundred and twenty-eight different ways 

 {i.e., 2"^), each combination being possibl}" 

 constant, and Mendel Avas fortunate enough to 

 obtain the full number of forms in the course of 

 his experiments with peas. Similar recombinations 

 have been obtained in many other plants and also 

 in animals, and it is not too much to say that 

 the special peculiarities of a considerable number of 

 the constant races of domesticated animals and 

 cultivated plants are nothing but recombinations of 

 characters previously existing in earlier races. 



