56 EVOLUTION AND GENETICS 



an exact record of the numbers of individuals of 

 different kinds that ajDpeared in the second and third 

 generations, but also because of his insight in inter- 

 preting the results that he obtained. 



Others had made crosses before Mendel. In fact, 

 a great deal of work had been done in making crosses 

 between wild species and also between cultivated 

 varieties. We realize today that the earlier crosses 

 between species failed to reveal the laws of heredity 

 because so many characters were involved that the 

 relationship of contrasted characters was obscured, 

 and that the crosses between domesticated varieties 

 failed either because the materials were not well 

 chosen, or else because the numerical relations in 

 the second generation were not observed. Some of 

 the earlier hybridologists, who worked before Men- 

 del's time and at about the same period, had ob- 

 served that the parental types may reappear in the 

 second and later generations. ISTaudin (1863, 1868) 

 had even suggested that this reappearance is due to 

 the separation of the parental types in the hybrid 

 but he failed to detect the numerical relations in- 

 volved and he did not make out the independent 

 inheritance of the members of different pairs of 

 characters. 



About twenty years after Mendel's results were 

 first announced, but before his results became gen- 

 erally known, Galton (1889-) formulated several 

 laws of inheritance based in part on data from plants 



