278 THE INTERNAL ENVIRONMENT OF THE BODY Part III 



(Fig. 15.1). It is relatively large in infants but becomes much smaller with 

 adolescence. It has been suspected of being one of the endocrine glands, but 

 never proven to be though it is often placed with them. Like the tonsils and 

 other lymphatic structures, it is concerned with the production of lymphocytes. 



