318 STUDIES, SCIENTIFIC AND SOCIAL 



one were then pale, slender, weak, and delicate, the other 

 ruddy, stout, and strong, these differences would be, in 

 one or the other, probably partly in both, " acquired char- 

 acters." And if both, at the same age, married twin 

 sisters, equally alike in childhood but who had been each 

 subject to corresponding conditions in after life, the com- 

 mon idea is that the children of the city couple would be 

 inherently weakly, those of the country couple strong; 

 and that the balance would not be restored even if these 

 two families of children were subject, during their whole 

 lives, to identical conditions. In other words, it is usually 

 believed that the acquired characters of the parents would 

 be transmitted to the constitutions of the children. But 

 it is now asserted, by Weismann and his followers, that 

 facts do not agree with this assumption, and that, in the 

 case supposed, both sets of children would inherit the 

 original qualities of the parents, modified, perhaps, by 

 qualities or characteristics of remoter ancestors, but would 

 not exhibit any effects of the changes produced in their 

 parents by external conditions only. 



This latter belief is, I am informed, held and acted upon 

 by breeders of animals as the result of their extensive 

 experience. If a young dog or horse of high breed and 

 good external points becomes accidentally lamed, so as to 

 be permanently disabled from the usual work of its kind, 

 it is often kept for many years to breed from, in full con- 

 fidence that its offspring will inherit the good qualities 

 of the stock, and will be in no way deteriorated by the 

 absence of work calculated to strengthen the muscles, 

 enlarge the chest, and otherwise increase the power and 

 activity of the parent. 



Results tliai sliould he Produced hy such Inheritance. 



Again, if the effects of the use of certain muscles, or 

 of special mental faculties with their corresponding 

 nervous and muscular co-ordinations, were transmitted to 

 offspring, then definite results ought to have been so 

 frequently produced as to have become embodied in 

 general experience and popular sayings. Take the case 



