96 VARIATION 



Blind people acquire a quickened and an educated sense of 

 hearing and a touch that amounts almost to a separate sense. 

 In the same way the developing of the bodily functions and 

 activities generally depends upon judicious use (exercise) ; and 

 the skill of the trainer and the results he is able to achieve 

 depend not only upon his knowledge of methods that will most 

 certainly insure the exercise of the desired parts but also upon 

 his judgment as to how severe and protracted that exercise 

 should be in order to secure the maximum effects of use and 

 not incur the destructive consequences of overuse. This is as 

 true in the feeding yard as upon the race track, and applies as 

 well to the raising of good and profitable feeders as to the devel- 

 oping of racing horses, the education of drivers and saddlers, the 

 training of hunting dogs, the " trying out " of homing pigeons, 

 or the teaching of canaries to sing by never allowing the young 

 birds to hear a false note. 



Influence of feed upon functional activity. The relation of 

 the amount of feed to its economical consumption is a subject 

 needing careful investigation. Enough is known to warrant the 

 assertion that animals can and do learn to take amounts far 

 larger than can be really used. When a steer consumes over 

 a bushel of corn a day he has simply formed the eating habit 

 as the result of a morbid appetite, nor is this appetite an indi- 

 cation of body needs or a guaranty of its powers to economically 

 convert the feed into meat, milk, or labor. 



It is significant that steers very gradually brought into full 

 feed will never take these enormous amounts. Professor H. W. 

 Mumford of the University of Illinois finds that under such cir- 

 cumstances twenty pounds of grain per day is all the animal 

 will take. 



Consumption of extreme amounts is, therefore, evidence only 

 of the quantities of feed the digestive tract can carry and dis- 

 charge without calamity, of its power to secrete gastric and 

 other digestive juices, and of the ability of the excreting organs 

 to eliminate unused and unusable surplus from the body 



In the case of Rose and Nora the latter consumed the same 

 feed as the former but returned but little more than half as 

 much. She was undoubtedly, from the standpoint of economy, 



