CHAPTER VII 

 UNIT CHARACTERS 



Unit of study • Species composed of definite characters • Every individual 

 possesses all the characters of the race • Characters developed and characters, 

 latent • Characters dominant and characters recessive • Correlation of charac- 

 ters • Lost characters • New characters • Characters and unit characters 



Unit of study. In attempting to discover the ultimate prin- 

 ciples involved in plant or animal improvement as we have 

 learned to understand it, the special object of study is not the 

 species as a whole nor even the individuals involved, but rather 

 the particular characters that give the species value to man, and 

 their relation to the general group of unit characters that com- 

 pose the race. This study is undertaken with the purpose of 

 developing a second method of improvement in addition to the 

 one by simple selection already outlined. 



Species composed of definite characters. It requires a little 

 careful thought to fully realize that all species are composed of 

 very definite characters, — some more prominent than others, 

 some especially prominent in certain individuals and secondary 

 in others, and still others that might be included, for all we 

 know or can see, but that yet are never found. 



For example, vertebrae and ribs are characters common to 

 many species, a hairy covering to vastly fewer, horns to fewer 

 yet, and smooth, sharp horns to very few. The short, smooth, 

 sharp horn, characteristic of the bison, and the large, flat, 

 corrugated one of the true buffalo are very different, the one 

 from the other, but each is found in no other species. There 

 is no evident reason why horses do not have horns like 

 most cattle, but the fact is that this character is absent in the 

 genus Eqmts. 



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