176 DOMESTICATED ANIMALS AND PLANTS 
Can modifications due to environment be transmitted? This 
is the old and much debated question of inheritance of acquired 
characters. It means in brief this: If a horse is spavined, will 
the spavin be transmitted to the offspring? If a man is a great 
musical performer, will his child be a better musician than if the 
parent never learned music ?. Also, would this musician’s younger 
children inherit more of the musical faculty than would the older 
children, born before the highest development of the parent’s 
powers ? 
Will the calf of a cow that has made a phenomenal record 
at the pail be itself a better cow than would the same calf from 
the same cow if she had only moderate feed and care? Will 
cutting off the horns of cattle tend to produce, by and by, a 
hornless race? 
This is the class’of questions involved at this point. The 
matter is too intricate for treatment here, except to say that, in 
the opinion of the author, the class of modifications here men- 
tioned are not transmitted ; for example, we have been cutting 
off the tails of lambs for many generations, but sheep are not 
yet born without tails. Heredity is not so easily influenced as 
all that, because the germ plasm (the sex cell) is not affected 
by an operation like dehorning or cutting off the tail. 
There is doubtless a class of modifications that may affect the 
germ plasm and therefore be transmitted. I refer to all-pervad- 
ing influences like temperature and alkalinity for lower organ- 
isms, and for the higher animals and plants, to nutrition and to 
definite chemical compounds, like poisons and toxins from con- 
tagious and infectious diseases, 
The student who desires to pursue this subject at length is 
referred to “ Principles of Breeding,” pp. 221-345, and collateral 
literature. 
Summary. What the offspring is at maturity depends, first of all, upon 
the possibilities born into him ; and second, upon the opportunities for their 
development afforded by the environment. Every individual inherits all 
the faculties of the race, both good and bad, yet the fact remains that 
