AND PERSONALITY 



through selective line breeding from the offspring of the 

 great foundation stallions Matchem, Herod, and Eclipse. 



We can account for this continual advance of the thor- 

 oughbred in only one way, namely, through the operation 

 of the law of orthogenesis. When a horse or a man exhibits 

 a progressive increase in the size of an organ or group of 

 organs, this progression may continue until the offspring 

 exhibits such extremes as to affect the line unfavorably. 

 In man, the brain, the heart, the thyroid gland, and the 

 sympathetic system have been increased in activity by the 

 operation of the law of orthogenesis to the ceiling of his 

 energy possibilities. In some cases the activity of man's 

 energy-controlling organs is so extreme that he is impaired 

 and destroyed by exophthalmic goiter, by hypertension, 

 by diabetes, and by nervous, mental, and heart diseases. 

 Therefore, we may expect that some day the thoroughbred 

 horse, in which the brain, the heart, and the adrenal-sym- 

 pathetic system have undergone an increase in size and 

 power, will, as in man, reach the pinnacle, and this achieve- 

 ment will be expressed by an increasing incidence of steril- 

 ity, nervous instability, and energy diseases not yet well 

 defined. Examples of such instability are seen in Brown 

 Eyes and Roxana. 



The thoroughbred Brown Eyes was out of Katy of the 

 West, by Caughkill, and the sire of Katy of the West was 

 Spendthrift, an outstanding race horse. Brown Eyes was a 

 horse of high promise; her owners believed that if she could 

 be started in a race she would be a winner. But because of 

 her excitability she could not be properly started. Her 

 behavior was clarified when we found the abnormal size 

 of the adrenal glands, the largest that we have seen in any 

 horse. These adrenal glands weighed 60.78 grams; the 

 ratio to the body weight was 1 19030 as contrasted with the 

 adrenal-to-body-weight ratio in Equipoise of 1:11187. 

 Brown Eyes is an example of a mutation so great as to 

 disqualify her as a race horse. 



135 



