102 THE GLANDS REGULATING PERSONALITY 



stress and strain. The Kinetic chain of organs, brain, adrenals, 

 liver, thyroid and muscles, began working together in desperate 

 situations for their possessor ages ago. Successful in helping him 

 to survive, they have survived as a functional unit. 



It was probably evolved in the Post-Tertiary Era, about twenty 

 million years ago, when the coming of the carnivores introduced 

 direct body-to-body conflicts, and their concomitants, a quick 

 and versatile nervous system. During the Tertiary epoch the 

 earth basked in the heat of a tropical sun nearly everywhere on 

 its surface. The luxuriant vegetation of the torrid zone flourished 

 and swarmed, for the temperature all over was what it is today 

 at the equator. Gigantic vegetarians were the animals, creatures 

 like the dinosaurs, enormous, gargoylean monsters, of an in- 

 credible size and strength, but clumsy and grotesque, with small 

 brains and little intelligence. For what need was there for brain 

 and intelligence when food lay about so abundantly at hand for 

 them to gorge themselves. As there was no competition for food, 

 there were no enemies. 



Then as the earth evolved and grew cooler, vegetation failed, 

 the ancestors of the present carnivora appeared, the fathers of 

 the wolf and tiger, light, lithe and pugnacious, with senses acute 

 and ferocious weapons of attack, who set out to destroy every- 

 body. They destroyed pretty nearly all of the huge leaf-eating 

 species, and only the more plastic and smaller ones, who were 

 more keen-sensed and swift- footed (of whom the deer and ante- 

 lope, horse and ox are the descendants), escaped. The smallest 

 either took to the air to become the bat, or, like the forerunners of 

 the squirrel and ape, took to the trees. 



It was the coming of the carnivores, therefore, that accelerated 

 the development of brain matter, and started the process which 

 created man. But in the millions and millions of years of con- 

 flicts, instincts grew into being that sank deep into bone and 

 marrow. The most fundamental reflexes, those immediate re- 

 sponses to irritation or danger, were laid down, and among them 

 the drive and check system. When the animal had decided to 

 fight its enemy or was forced to fight, or determined to prey, 

 then was the time for the drive system to do its utmost to speed 

 up everything that would help in the fight, while the check 

 system came into play to hinder whatever would interfere 

 or burden in the fray. First the drive mechanism must have 

 hit upon, and then the value of the check devices must 

 have been found in fear and flight, and especially in hiding and 



