LIFE HISTORY 59 



the activity and hyperplasia of the subepithehal lym- 

 phatic glands. 



At or about the time of puberty a diminution in the 

 size of these glands takes place, and in later years, 

 when presumably a high degree of immunity has been 

 attained, they have usually undergone a partial 

 atrophy. In extreme old age the constituent lymph 

 nodules have greatly diminished in size and number 

 and the subepithelial lymphatic glands are quite in- 

 conspicuous. Doubtless many of the lymphatic 

 nodules have undergone inflamniation followed by 

 absorption or fibosis but a true process of atrophy 

 seems to be mainly responsible. 



