150 DOMESTICATED ANIMALS 



five-toed to the single-toed form was slowly accomplished, and 

 to its doing went a great many temporary forms, which served, 

 we may say, as stepping-stones for the ongoing. So far as 

 we can judge, these intermediate forms were small, rather frail 

 creatures, which probably could not have been made to serve 

 any purpose useful to man. It was not until the mechanical 

 system of the large single toe with the wonderfully developed 

 nail, which makes up the foot and hoof of the horse, had been 

 attained, that the creature becomes fit for the wonderful work 

 we have persuaded him to do in our civilization. 



A comparison of the skulls of the Tertiary mammals 

 and those of our own day indicates that in certain of the 

 important series, and presumably in them all, the brain has 

 increased in size from the earlier to the later times. This 

 increase in brain capacity has doubtless been attended by a 

 decided gain in the measure of intelligence, a gain which has 

 doubtless served to make the modern representatives of the 

 series fitter for man's use than their ancestors were. For, while 

 the number of our very useful domesticated forms may seem 

 at first sight to be dull of wit, none of them are really low in 

 the intellectual scale as we apply it to the brute ; in fact, a 

 considerable measure of intelligence is absolutely required as 

 a condition for true subjugation. This is seen by the fact 

 that nothing like a real adoption into our social system has 

 ever been accomplished except with a few of the higher orders 

 of mammals and birds, species which have an intellectual 

 capacity that we recognize as akin to our own. Thus, so far 

 as we can see, man's appearance on this stage was, so far as 

 it relates to the possibility of companionship with the lower 

 life, exceedingly well timed. He came at a period when the 

 life was ready to give him and to receive from him a large 



