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 1,he 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 



