288 WILD TRAITS IN TAME ANIMALS. 



ordinary circumstances the number of wild ducks 

 remains pretty constant from year to year. This 

 means that out of every family of fourteen 

 (taking twelve to the average brood) as a rule 

 only two survive to breed in the following 

 spring. Now we know that when wild animals 

 are closely observed they are found to differ 

 from one another as much in mental and physi- 

 cal characters as do human beings. Hence 

 among each brood of wild ducklings there 

 would always be dullards or weaklings which 

 would fall a prey to watchful enemies or else 

 perish from disease or accident. We find that 

 in most cases where a large number of young 

 are produced every year, infantile mortality 

 accounts for by far the greater part of the 

 annual waste. Now, among tame birds the 

 young are carefully nursed and are never pur- 

 posely destroyed, because they are of no value 

 until they have obtained their growth. More- 

 over, instead of being selected for breeding 

 purposes on account of their alertness or ac- 

 tivity, they are chosen on a principle which 

 often ensures the possession of exactly opposite 

 qualities. What civilised man wants is a duck 

 of a placid and greedy disposition which will 



