220 



BIOLOGY OF DEATH 



THE PITUITARY GLAND AND DURATION OF LIFE 



Eobertson has been engaged for a number of years 

 past on an extensive series of experiments regarding the 

 effect of various agents upon the growth of white mice. 

 The experiments have been conducted with great care 

 and attention to the proper husbandry of the animals. 

 In consequence, the results have a high degree of trust- 

 worthiness. In the course of these studies he found that 

 the anterior lobe of the pituitary body, a small gland at 

 the base of the brain, normally secretes into the blood- 

 stream minute amounts of an active substance which has 

 a marked effect upon the normal rate of growth. By chemi- 

 cal means, Eobertson was able to extract this active sub- 

 stance from the gland in a fairly pure state, and gave to it 

 the name tethelin. In later experiments, the effect of 

 tethelin, given by the mouth with the food, was tried in 

 a variety of ways. 



In a recent paper, Eobertson and Eay have studied 

 the effect of this material upon the duration of life of the 

 white mouse with the results shown in Table 27. 



TABLE 27 



Effect of tethelin on duration of life in days of white mice. 



(Robertson and Ray) 



From this table, it is apparent that the administration 

 of tethelin with the food from birth to death prolonged 



