478 [March 12, 



and is most abundant at the points where the aggregation of 

 epithelial cells shows that the feathers and hairs are about being de- 

 veloped. The horny structures contain it plentifully ; in the bill, 

 the hoof, and the claws it exists in large proportion. From the hoof 

 of a foetal calf of about four months enough may be obtained, by the 

 alcoholic solution of potash, for chemical examination and fermenta- 

 tion. The muscular tissues of the foetus are full of it ; from 20 

 to 50 per cent, can be extracted from the muscles of foetal calves 

 of from three to seven months by the aid of the alcoholic solution of 

 potash. 



Having arrived, by a repetition of Dr. Pavy's ingenious experi- 

 ments, at the conclusion that the amyloid substance of the liver is 

 not normally changed into glucose, and finding on examination the 

 accuracy of the facts concerning the physiological relations of the 

 amyloid substance to the foetal and other tissues, discovered by M. 

 Charles Rouget, and investigated by Bernard himself, the question 

 presents itself, May it not be that the liver does for the adult what 

 divers tissues do during the development of the foetus ? May not 

 this great organ form, with the help of the amyloid substance se- 

 creted in its cells, a nitrogenous compound, just as the muscles of 

 the foetus convert the amyloid substance contained in them into the 

 highly nitrogenous material of muscular tissue ? 

 . May not, in fact, the amyloid substance of the liver be the basis 

 of an azotized protoplasma forming a constituent of the blood of the 

 adult animal, as the amyloid substance of muscle is the basis of the 

 material from which the evolution of muscular tissue is accom- 

 plished ? 



Even a superficial consideration of the functions performed by the 

 liver leads one to answer these questions in the affirmative. For if 

 it be true that the blood which enters the liver is rich in fibrine and 

 albumen, and that these materials are so completely changed within 

 this organ that little or none of them leave it by the hepatic vessels, 

 what becomes of them ? It is true their hydrocarbonous constitu- 

 ents may be thrown out as bile. But what of the nitrogen contained 

 in them ? If it does not escape by the bile-ducts, it has no other 

 mode of exit save by the hepatic vessels. The author conceives it to 

 be reunited with the hydrocarbonous amyloid substance, and to leave 

 the liver as a newly-formed proteic compound, partly perhaps as 



