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, vertebrze 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 /guzs. 
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