322 



Biology in Ame7'ica 



tial eiierfry is convert chI into active or kinetic energy, and the 

 tissues of the body sutler corresponding loss. According 

 to Crile certain pai-ts of the brain furnish the nervous en- 

 ergy, which is probably identical with electrical energy, and 

 wliich controls muscular, and otlier activity. The adrenal 

 ghiiids furnish adrenalin, which in some way determines the 

 oxidation processes in the brain to which the nervous energy 

 is due. The thyroid gland, which Crile calls the ''pace- 

 maker" of the body, furnishes iodin to the tissues and ren- 



Effect of the Kinetic Drive 



Photograph of a sohlier under extreme mental and physical stress. 

 From Crile, " Tlie Kinetic Drive." "Journal of the American Medical 

 Association," Vol. LXV. 



ders them more permeable to the nervous impulses. In the 

 conversion of energy in 'the body certain acid waste products 

 are formed which are eliminated by the liver, kidneys and 

 lungs. The blood is thus kept alkaline, in Avhich condition 

 only is the carriage of oxygen to the tissues possible. 



If the production of adrenalin, the secretion of the ad- 

 renal glands, be prevented, either by removal of these glands, 

 by cutting the nerves which supply them or by narcotizing 

 the latter Avith morphin, activity is reduced. On the other 

 hand administration of adrenalin produces results similar to 



