1332 PHYSIOLOGY 



with tumours of the pituitary gland. This disease consists in an 

 increased growth of certain parts of the skeleton, especially the lower 

 jaw and the extremities of the limbs. Headache is often present, 

 and there may be polyuria and affection of the eyesight. When this 

 disease occurs during the period of active growth there may be an 

 increase in length both of the limb-bones and of the trunk, and most of 



6 c d 



/ J 





FIG. 548. Section of cat's pituitary body, passing through the cleft in the gland. 



(P. T. HERRING.) 



a, pars anterior ; 6, cleft ; c, pars intermedia ; d, pars nervosa (posterior 



lobe). 



the giants, which are shown from time to time, are examples of this 

 pathological condition of ' gigantism.' Opinions have differed whether 

 this condition is due to an over-action or to a failure of action on the 

 part of the gland. Experiments on extirpation of the gland have not 

 solved the problem. Total extirpation of the pituitary body is 

 generally followed by death within a few days, death which cannot be 

 attributed to shock or any accidental features of the operation. One 

 must regard the pituitary therefore as essential to the maintenance 

 of life. It has not been possible by transplantation to replace a 

 removed pituitary body, since the transplanted organ has hitherto 

 always undergone degeneration. In some cases Gushing succeeded in 

 prolonging the period of survival after extirpation of the pituitary 



