THE LIVER FORMATION OF AMYLOID SUBSTANCE. 485 



is compact, is much less than in those in which it is loose. In the Horse, 

 for example, it is at least three times less than in the Rabbit. In Fowls, 

 Briicke found it might reach the high proportion of 12 per cent, of the 

 total weight of the Liver. In rabbits submitted for several days prior to 

 death to different dietaries, it has been found that cane, milk, and grape 

 sugar (though not nianuite), 1 and starch always led to a large percentage of 

 amyloid substance in the Liver, this organ appearing to seize upon these 

 substances and store them up, so that the sudden entry of a large quantity 

 into the general circulation is prevented. If, however, a very considerable 

 quantity of sugar be introduced into the stomach, especially if it be empty 

 (as it commonly is in the dog), it is quickly absorbed, and though conveyed 

 to the liver, this organ is unable to metamorphose the whole of it, and the 

 portion which escapes entering the general circulation is discharged by the 

 Kidneys, providing it exceeds three per cent, of the blood. The same 

 quantity of Sugar may be disposed of without producing diabetes if it be 

 ingested slowly, or when the stomach is full (as it commonly is in rabbits), 

 and thus Bernard accounts for the difference in regard to the appearance of 

 Sugar in the urine after the administration of the same quantity to dogs and 

 rabbits. 2 Although, as the foregoing experiments show, the amyloid sub- 

 stance is much more abundant in the livers of animals fed on starch and 

 sugar, from which, therefore, it doubtless in part proceeds, it must not be 

 overlooked that it is also present in animals confined to a pure meat diet ; 

 in which case it is probable, that it proceeds from the disintegration of al- 

 buminous compounds into hydrocarbonaceous and nitrogenized substances. 3 

 In Granivorous and Herbivorous animals, as in fowls and rabbits, the 

 albuminous compounds do not appear to be well adapted for the production 

 of glycogeu. Thus Weiss 4 found only traces of Glycogen in the liver of 

 fowls fed for a fortnight on flesh and fibrin, and Dock found none in rab- 

 bits fed with white of egg. The same conclusion may be drawn from the 

 fact that the quantity of glycogen in the liver of animals starving to death, 

 and when therefore they are living on animal diet, is greatly reduced. In 

 1859, Bernard 5 detected the presence of amyloid substance in the placenta 

 of ruminants, in which, or rather, as has been since shown, in patches of 

 cells lying on the inner surface of the amnion, it exists in considerable 

 quantities. Shortly afterwards, Rouget 6 discovered it in various embryonic 

 cellular tissues, as in the epithelium of the skin, and of the alimentary and 

 geuito-uriuary mucous membranes. It is remarkable that it is not found in 

 the liver till its histological development is completed, or until about the 

 middle of intrauterine existence. Substances presenting the reactions of 

 starch or of dextrin have recently been discovered by Jaffe in the substance 

 of the brain, by Limpricht 7 in the muscles, and by Kiihue in various glands 

 and pathological growths. Amyloid substance has been found also in the 

 bodies of several invertebrate animals, as in the snail (Bernard), cockle 

 (Bizio 8 ), tape and round worm (M. Foster 9 ), mussel, and oyster (Pavy 10 ) ; but 



1 See Lueh^inger, Pfliiger's Archiv, Bd. viii, and Salomon, Virchow's Archiv, 

 Band !xi, p. 352. 



2 See Bninton, Lectures in British Mod. Journal, 1874, pp. 1, 39, and 221; and 

 Schoptter, Archiv f Experiment. Path., 1873, i, p. 72. 



3 See Hoppe-Seyler, Pfluger's Archiv, Bd. vii,p. 399. Salomon (Virchow's Archiv, 

 Bd. Ixi, 1874, p. 352) has demonstrated clearly that glycogen is formed in the liver 

 from gelatin as well as from albumen. 



4 Sitzungsber. d Wien. Akad., Bd. Ixvii, ahth. 3. 



5 Brown-S6quard's Journal de. la PhyMol., 18'/l, p. 30. 6 id., p . 83. 



7 Annalen der Chemie und Pharm., Bd. cxxxiii, p. 293. 



8 Comptes Kendus, Ixii, p. 675. 



9 Proceedings of the Koy. Soc., 1865, No. 79. 10 Op. cit., 18G8, p. 77. 



