ORIGIN OF ITS CONSTITUENTS. 297 



alkaline salts of the fatty acids exist in the chyle of the thoracic 

 duct than in that of the smaller lacteals or even than in the blood, 

 these saponified fats cannot originate from the lymph that is mixed 

 with the chyle, or from the plasma of the blood, but must rather 

 be owing to saponification within the lacteals themselves. 



The two following questions especially force themselves upon 

 our notice, in considering the origin of the albuminous substances 

 contained in the chyle: 1. Is the fibrin found in the chyle formed 

 within that fluid, or does it originate in the intercellular fluid 

 transuded from the blood ? and 2. Does the albumen reach the 

 intestinal villi in its perfect state, or are the absorbed peptones 

 elaborated into albumen within the cells of the villi and in the lac- 

 teals ? In respect to the latter of these questions, we have already 

 (at pp. 104 and 123) indicated the grounds which have led us to the 

 view that the peptones are not converted into albumen in the intes- 

 tinal canal itself, notwithstanding the incontrovertible facts which 

 have been advanced by Frerichs in favour of the opposite opinion. 

 The system of cells through which the absorbed albuminous sub- 

 stances (and consequently the peptones, according to our view) have 

 to pass before they can enter their proper vessels (the lacteals) and 

 the abundant net- work of capillaries enclosing these cells, appear 

 to us clearly to indicate that these substances have here still to 

 undergo important changes, whose final product can scarcely be 

 anything else than true, coagulable albumen containing alkali. It 

 has further been found that the chyle after its passage through the 

 mesenteric glands, is richer in albumen than it previously was ; and 

 this augmentation is solely referable to the absorption of blood- 

 albumen in the glands. In proportion to our certainty on these 

 points, so much the more probable it becomes that the augmen- 

 tation of the albumen, at all events in part, depends upon the 

 complete metamorphosis of the peptones into coagulable albumen. 



In regard to the second question, we must remain undecided 

 between the opposite results of Prout* and of Tiedemann and 

 Gmelin,t as to whether the chyle contains true fibrin before its 

 passage through the glands, or whether the coagulum observed by 

 the former chemist, did not consist of fat, cells, and other albumi- 

 nous matters. If the plasma actually passes from the blood into the 

 lacteals, which, indeed, cannot be doubted, it would seem most 

 probable that the whole of the small quantity of fibrin which is 

 contained in the chyle originates from the blood or from the lymph. 



Annals of Philos. Vol. 13, pp. 12 and 265. 

 t Op. cit., p. 157. 



