1863,] 477 



not, from the consideration of these functions, led to infer that the 

 nitrogen which leaves the liver by no other outlet may go forth in 

 the hepatic blood in union with the amyloid substance thus changed 

 into a new azotized principle ; that thus the liver is a great blood- 

 making organ, in which there is constantly going on a reconstruction 

 of certain ingredients of the blood ; that in it the fibrine, &c., which 

 has done its work, is disintegrated, the hydrocarbons of the bile 

 abstracted, and the nitrogen combined with the amyloid substance, 

 which, instead of being normally changed into sugar, emerges from 

 the liver a constituent principle of the protoplasma, from the bosom 

 of which (to use the words of Bernard with reference to the foetal 

 tissues) organic evolution is to be accomplished ? 



Of the existence of the Amyloid Substance of Bernard in the 

 Placenta and other Organs and Tissues. 



The cells of the placenta contain, during the earlier stages of 

 embryonic life, animal dextrine, having characters identical with 

 those of the amyloid substance of the liver ; its presence may be 

 readily demonstrated under the microscope. Bernard has discovered 

 it in the placentae of rabbits, guinea-pigs, &c. He also made the 

 very interesting observation that the multiple placentulse of the 

 ruminants do not contain any amyloid substance, but that in this 

 class of animals this substance is found in certain cells of the 

 amnion. The presence, however, in the amnion or the placenta, 

 of epithelial cells containing amyloid substance, is a fact quite se- 

 condary to the general fact that this substance enters largely into 

 the constitution of most of the tissues of the embryo. Its existence 

 does not indicate a new function of an organ doing temporarily 

 the duty of the liver, but it indicates a new fact with regard to 

 the development of certain structures and a new property of tissue. 

 During embryonic life a great part of the fcetal tissues are found 

 to be so impregnated with amyloid substance, that it appears to be 

 the formative material from which these tissues are evolved ; and, 

 in fact, it would seem to be related to their growth and development, 

 as starch is to the growth and development of the tissues of vege- 

 tables. In the skin of the chick in ovo, and of the foetuses of 

 rabbits, cats, guinea-pigs, sheep, oxen, pigs, it is readily demon- 

 strated ; it is seen by the addition of acidulated tincture of iodine, 



VOL. XII. 2 M 



