Theory and Practice in Breeding, 177 



tions and that so little theoretical formal experimenta- 

 tion has been done in breeding. 



During recent years there has been a movement 

 into studying these subjects statistically. Plants and 

 small animals, which can be "grown in large numbers 

 with little expense and under control conditions alike 

 for each and all, serve for making records for deter- 

 mining facts. 



Mendel, a German monk, thus used peas and 

 worked out some most interesting facts. His results, 

 now known as the Mendelion Laws, were very surpris- 

 ing. He found that where two varieties differed in 

 some strong dominant, as one pea white and another 

 pea blue, one pea wrinkled and the other pea smooth, 

 that the progeny was in the first case part pure white, 

 part pure blue and in the second case part pure mixed, 

 or unstable in their heredity. That is, in the self-pollen- 

 ated species, a characteristic long inbred so as to be 

 strongly dominant in the plant form would not readily 

 coalesce or mix with an opposite character. In the sec- 

 ond year part of the pea hybrids were part \vhite and 

 part blue, arid these peas which followed one or the 

 other of the original parent, when planted and their flor- 

 ets allowed to self- fertilize, produced progeny which all 

 followed the white, the blue, the wrinkled or the 

 smooth-seeded parent, as the case might be. It was 

 as if the dominant Roman nose followed the family 

 through succeeding- generations where there is marry- 

 ing into another race. A portion of the seeds, however, 

 retained the mixed dominance of their hybrid character 

 but these also generation after generation partly broke 

 up into pure white, pure blue, pure wrinkled and 

 pure smooth forms until nearly the whole race had 

 reverted back in its individual characteristics to the 

 several original forms. And stranger still, this break- 

 ing up seems in some species to occur in mathematical 

 proportions. 



Mendel thus worked out facts which may be worth 

 much in breeding. It may assist in combining as dom- 



