INFLUENCE OF HEREDITY. 307 



into milk is hereditary in a large measure and is usually 

 transmitted to the offspring. 



The peculiar propensities of some kinds of animals to lay 

 on flesh in certain parts of the body is another illustration, 

 and one which is of great practical value to stockmen. Fe- 

 cundity, also another point which is of vital interest to the 

 stockman, is in a large measure hereditary. In the case of 

 swine certain families have larger litters than others; the 

 same is true in sheep and other classes of animals. 



Certain peculiar color markings have also been known to 

 be hereditary. There are numerous other illustrations which 

 might be cited in this connection as belonging to what we call 

 normal characteristics, or those which are not unusual. 



Another class of characteristics which are hereditary are 

 those which belong to the acquired or abnormal class. In 

 the acquired class may be placed those characteristics which 

 have been developed by the conditions in which they are 

 placed or the peculiar training they have received at the 

 hands of man. 



A few illustrations of this form will suffice to show the 

 influence of this law. The tendency of the dairy cow to give 

 a large flow of milk, which is due in no small measure to the 

 influence of man, is hereditary. In the case of dogs we find 

 certain well defined traits which are transmitted to the young. 

 Young setters, pointers and retrievers, that have never been 

 in the field, will often work with as much steadiness as a 

 dog of long experience. This is an excellent illustration of 

 heredity. These are but a few of many examples which might 

 be cited. 



Another class of characteristics which are oftentimes in- 

 herited are those of a rather unusual nature called abnormal. 

 They represent something unusual in the way of a freak. 

 In certain human families the presence of an extra toe or 

 finger in one of the parents has oftentimes been transmitted 

 to the children. In some instances of this kind every one of 

 some half a dozen children born to such parents have had 

 six fingers or toes, while in other instances one or two mem- 

 bers of the family would be thus affected and the remainder 

 be normal. In some instances the normal members of the 

 family gave birth to children with six fingers or toes. Take 

 the Dorking breed of fowls which has the fifth toe as one 

 of its characteristics at the present time, in early days had 



