TRANSMISSION OF MODIFICATIONS 



353 



In nature, where selection is unlimited, it does not greatly 

 matter whether modifications thus induced are directly or indi- 

 rectly transmitted, the only difference is a slight one in the 

 amount of time required; but among domesticated species, where 

 selection is largely controlled, where it is to be employed for as 

 few purposes as possible, and where at most, for economic rea- 

 sons, its use must be sparing as compared with that of nature, 

 here it is important to know, if possible, whether there exists, 

 side by side with our selection, this other influence, in some cases 

 assisting, in others opposing, our aims. 



The influence of the environment upon transmission is cer- 

 tainly slight at any moment, but if it exists at all it is cumulative, 

 and, being independent of selection, it is a friend to the breeder 

 for fixing desirable characters, as it is also an insidious enemy, to 

 be greatly dreaded, when an undesirable character is involved. 



As the discussion proceeds the student must realize that we 

 are looking for that which is at best but an infinitesimal incre- 

 ment as compared with the larger results due to selection, the 

 presence and influence of which he must grow skillful in detect- 

 ing and assessing. 



He must also be upon his guard against evidence that is not 

 evidence. For example, a cat learns to open a door, or a mare 

 to hold up her foot for her feed. If the young develop the same 

 habit as the mother, the hasty observer calls it a case of the 

 inheritance of an acquired character ; whereas the truth is that 

 in all probability the young creatures simply learned it by obser- 

 vation ; indeed the readiness of the young to learn by imitation 

 is vastly underrated. In the case of the horse it must also be 

 remembered that most individuals that hold up the foot when 

 begging have defective voices. This defect is extremely likely 

 to be transmitted to the young, which, finding themselves voice- 

 less, would, if left to themselves, even entirely without example, 

 resort to the next most convenient and natural method of beg- 

 ging, which is holding up the foot. It must not be forgotten 

 that, in the horse, holding up the foot in begging is a kind of 

 fundamental instinct, second only to vocal effort, and it may 

 be said in general that if a horse cannot call for his feed he 

 will hold up his foot. Against such instances as these, urged 



