294 ABSORPTION AND SANGUIFICATION. 



meal has been taken ; and that the turbidity increases for some hours 

 subsequently, after which it disappears. The period at which the dis- 

 coloration is greatest, and the length of time during which it continues, 

 vary according to the digestibility of the food. When the serum is 

 allowed to remain at rest, the opaque matter rises to the surface, pre- 

 senting very much the appearance of cream ; and when separately 

 examined, it has been found to contain a proteine-compound, mingled 

 with oily matter, the relative amount of the two appearing to depend 

 in part upon the characters of the food ingested. Hence it would seem 

 probable that the molecular base of the chyle is partly derived from 

 albuminous matter of the food ; more especially as it is known that 'oily 

 particles,' when introduced into an albuminous fluid, become surrounded 

 with a pseudo-membranous pellicle. The gradual disappearance of the 

 turbidity of the serum, indicates that the substance which occasioned it 

 no longer exists as such in the circulating current ; being either drawn 

 off by the nutritive or secretory operations, or being converted by the 

 assimilating process into the ordinary constituents of the blood. 



518. During the passage of the Chyle along the lacteals, towards the 

 Mesenteric glands, it undergoes two important changes ; the presence 

 of Fibrine begins to manifest itself by the spontaneous coagulability of 

 the fluid ; and the oil-globules diminish in proportional amount. The 

 fibrine appears to be formed at the expense of the albumen ; as this 

 latter ingredient undergoes a slight diminution. It is in the' chyle 

 drawn from the neighbourhood of the mesenteric glands, that we first 

 meet with the peculiar floating cells, or chyle-corpuscles, formerly 

 adverted to ( 214), in any number. The average diameter of these is 

 about l-4600th of an inch; but they vary from about l-7000th to 

 l-2600th, that is, from a diameter about half that of the human blood- 

 corpuscles, to a size about one-third larger. This variation probably 

 depends in great part upon the period of their growth. They are usually 

 minutely granulated on the surface, seldom exhibiting any regular nuclei, 

 even when treated with acetic acid ; but three or four central parti- 

 cles may sometimes be distinguished in the larger ones. These corpus- 

 cles are particularly abundant in the chyle obtained by puncturing the 

 mesenteric glands themselves ; and there can be little doubt, that they 

 are identical with the altered epithelium-cells, which line the lacteal 

 tubes in their course through those bodies ( 496). 



519. The glandular character of these cells, and their continued pre- 

 sence in the circulating fluid, seem to indicate that they have an 

 important concern in the process of assimilation, that is, in the con- 

 version of the crude elements derived from the food, into the organizable 

 matter adapted to the nutrition of the body; in other words, in the 

 conversion of Albumen into Fibrine ; which change would seem to take 

 place to a considerable extent in the Mesenteric glands. For it is only 

 in the Chyle which is drawn from the lacteals intervening between the 

 mesenteric glands and the receptaculum chyli, that the spontaneous 

 coagulability of the fluid is so complete, as to produce a perfect sepa- 

 ration into clot and serum. The former is a consistent mass, which, 

 when examined with the microscope, is found to include many of the 

 chyle-corpuscles, each of them being surrounded with a delicate film of 



