472 SECKETIOK 



Alleged Production of Fat ly the Liver. It is stated by Bernard that, in animals fed 

 largely with saccharine and amylaceous principles, the blood of the hepatic veins contains 

 an emulsive matter, which seems to be fat combined with a proteine substance. In sup- 

 port of the opinion that fat is thus produced in the liver, he brings forward the well- 

 known fact, that a diet of starch and sugar is particularly favorable to the development 

 of adipose tissue. But the examinations of the matter supposed to be fatty have not been 

 sufficiently minute to lead to any positive conclusions with regard to its character or 

 composition. While there can be no doubt of the formation of fat in the organism inde- 

 pendently of the fat taken as food, there is not sufficient ground for regarding the liver as 

 one of the organs specially concerned in its production. 



Changes in the Albuminoid and the Corpuscular Elements of the Blood in passing 

 through the Liver. In verifying the observations of Bernard upon the presence of sugar 

 in the blood of the hepatic veins, Lehmann was led to observe other differences in the 

 composition of the blood from these vessels, as compared with the portal blood and the 

 blood of the arterial system. One of the most important of these was the absence of 

 coagulating principles. While the portal blood coagulates strongly, like blood from any 

 other part of the body, the blood of the hepatic veins does not coagulate, and " the fibrin 

 is either entirely absent, or is present in mere traces." 



Some very curious observations were also made by Lehmann upon the blood-corpuscles 

 in the hepatic vessels. He estimated that the proportion of white corpuscles in the blood 

 of the hepatic veins was at least fivefold the proportion in the portal blood. He also 

 noted certain differences in the appearance of the red corpuscles, which he explained by 

 the supposition that the liver was the seat of development of these elements, which were 

 formed from the white corpuscles, and that the blood of the hepatic veins contained a 

 greater number of " newly-formed or rejuvenescent blood-corpuscles." 



It is not our purpose, in this connection, to discuss the development of the corpuscular 

 . elements of the blood ; but it is interesting to note the above-mentioned changes in the 

 blood as it passes through the liver. The physiological significance of the destruction of 

 albuminoids is not understood, although the fact is undoubted. 



CHAPTER XIY. 



THE DUCTLESS GLANDS 



Probable office of the ductless glands Anatomy of the spleen Fibrous structure of the spleen (trabeculse) Malpi- 

 ghian 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 

 Extirpation of the spleen Anatomy of the suprarenal capsules Cortical substance Medullary substance 

 Vessels and nerves Chemical reactions of the suprarenal capsules State of our knowledge concerning 

 the functions of the suprarenal 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 resembling, in some regards, the true 

 glands, but without excretory ducts, have long been the subject of physiological specula- 

 tion; 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 passing through its substance dimly fore- 

 shadowed 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 physiologists as the most 



