AND PERSONALITY 



sympathetic nerves never become enlarged by use, and 

 the brain and the sympathetic system do not shrink 

 through disuse. 



On the other hand, the thyroid and adrenal glands vary 

 in size according to use and disuse. Since the temper, power, 

 and personality of the lion in captivity, as well as of the lion 

 in the wild state, are expressed primarily by the adrenal- 

 sympathetic system and since this is the only system that 

 provides the intensity of the flash of energy, we should 

 expect to find that the adrenal glands of the wild lion 

 would be larger relatively and absolutely than the adrenal 

 glands of the lion in captivity. 



We found just that! The adrenal glands of the lions 

 taken in the wild state were 25 per cent larger than the 

 adrenal glands of the nine "house guests of civilized 



man." 



Perhaps our greatest surprise was at the large size of the 

 goiter in the great Bengal tiger that had often been ex- 

 hibited as a performer in Beatty's Circus. Because his eye 

 had been injured we were able to secure this adult animal 

 in prime condition. As we have already stated, the celiac 

 ganglia have more branches and are larger and the plexuses 

 are larger and more complex in the lion and in the tiger 

 than in any other animal of comparable size. This signifi- 

 cant fact is correlated with another equally significant fact, 

 namely, that no other animal of comparable size can 

 execute an equal outburst of energy. 



In this connection it is significant that that great primate, 

 the gorilla, which defends itself and its family by sheer 

 power against the lion and the leopard, possesses so violent 

 a temper and so great an equipment for outburst energy 

 that only few survive captivity, and it is rarely that a 

 gorilla bred in captivity lives to adult age. Through the 

 kindness of Dr. William K. Gregory and Dr. Henry C. 

 Raven of the American Museum of Natural History, Dr. 

 Quiring and I were permitted to take measurements of the 



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