CHAPTER XI. 



THE DUCTLESS GLANDS. 



Probable office of the ductless glands Anatomy of the spleen Fibrous struc- 

 ture of the spleen (trabeculse) Malpighian bodies Spleen-pulp Vessels 

 and nerves of the spleen Some points in the chemical constitution of the 

 spleen State of our knowledge concerning the functions of the spleen 

 Variations in the volume of the spleen during life Extirpation of the 

 spleen Anatomy of the suprarenal capsules Cortical substance Medul- 

 lary substance Vessels and nerves Chemical reactions of the suprarenal 

 capsules State of our knowledge concerning the functions of the supra- 

 renal capsules Extirpation of the suprarenal capsules Addison's disease 

 Anatomy of the thyroid gland State of our knowledge concerning the 

 functions of the thyroid gland Anatomy of the thymus Pituitary body 

 and pineal gland. 



CERTAIN organs in the body, with a structure resem- 

 bling, in some regards, the true glands, but without excre- 

 tory ducts, have long been the subject of physiological spec- 

 ulation ; and the most extravagant notions concerning their 

 functions have prevailed in the early history of the science. 

 The discovery of those functions of the liver which consist 

 in modifications in the composition of the blood dimly 

 indicated the probable office of the ductless glands ; for, as 

 far as the production of sugar is concerned, the liver belongs 

 to this class. Indeed, the supposition that the ductless glands 

 effect some change in the blood is now regarded by physiol- 

 ogists as the most reasonable of the many theories that have 

 been entertained concerning their office in the economy; 

 and this view is adopted by those, even, who do not admit 

 the existence of a glycogenic function in the liver. Under 



