ELABORATION OF CHYLE AND LYMPH. 423 



medical man is familiar. Thus, in the various forms of Cancer, it has been 

 shown by Miiller and others, that the new growth consists of a mass of cells ; 

 which, like the Vegetable Fungi, develop themselves with great rapidity ; 

 and which destroy the surrounding tissues by their pressure, as well as by 

 abstracting from the blood the nourishment which was destined for them. 

 These parasitic masses have a completely independent power of growth and 

 reproduction ; and it seems difficult to refuse them the title of distinct exist- 

 ences. They can be propagated by inoculation, which conveys into the 

 tissues of the animal operated on the germs of the peculiar cells that constitute 

 this morbid growth ; and these soon develop themselves into a new mass. 

 It seems to be by the diffusion of the germs produced in one part through the 

 whole fabric, by the circulating current, that the tendency to re-appearance 

 (which is one great feature in the malignant character of these diseases) is 

 occasioned. Yet there is no evidence that the first production of a Cancerous 

 growth is due to germs introduced from without ; in fact, as it appears to the 

 Author, the history of its origin, as well as the analogy of similar cases, makes 

 it far more probable that the Cancer-cell is but a degenerated form of the ordi- 

 nary tissue of the body, being, in fact, a cell which possesses, to an unusual 

 degree, the power of reproduction instead of undergoing those transformations 

 by which it would be converted into other kinds of tissue ( 645). Several 

 instances have been recently published of the occurrence of Vegetable organ- 

 isms as parasites upon the Animal body ; that in some of these a true Plant, 

 possessing a regular apparatus of nutrition and reproduction, has arisen from 

 a germ introduced from without, there can be little question ; but in other 

 instances (as in the case of the crusts of Porrigo favosa] it has been assumed 

 that the organization is Vegetable, because it consists of a mass of cells capable 

 of extending themselves by the ordinary process of multiplication. But it 

 must be remembered that the cellular organization is common to Animals as 

 well as to Plants ; being the only form that manifests itself at an early period 

 of development in either kingdom ; and remaining throughout life in those 

 parts, which have .not undergone a metamorphosis for special purposes. , 

 Hence to speak of Porrigo favosa, or any similar disease, as produced by the 

 growth of a Vegetable within the Animal body, appears to the Author a very 

 arbitrary assumption ; the simple fact being, in regard to this and many other 

 structures of a low type, that they present the simplest or most general kind 

 of organization.* Their nature must generally be decided by their Chemical 

 constitution ( 16) ; and this, in the case of the Porrigo favosa, appears to be 

 unquestionably Animal. 



III. Elaboration of Chyle and Lymph. 



563. The Chyle, as first absorbed in the Lacteals, is very different, both in 

 its physical and chemical characters, from that which may be obtained from 

 the larger absorbent trunks, and from the Thoracic Duct ; for during its pas- 

 sage through these vessels, and their ganglia or glands, it undergoes important 

 alterations, which gradually assimilate it to Blood. The chyle drawn from 

 the lacteals that traverse the intestinal walls, contains Albumen in a state of 

 complete solution ( 467) ; and it is entirely destitute of the power of coagula- 

 tion, no fibrin being present in it. The Salts, also, are completely dissolved ; 

 but the Oily matter presents itself in the form of globules of variable size.t It 



* The Author is strongly inclined to bel'ieve that the propagation of many diseases by 

 inoculation, essentially consists in the implanting of cell-germs from one animal in the 

 body of another. The structure of the Vaccine Vesicle appears to him to point clearly 

 to such a view. 



f These oily globules are more abundant in the Chyle of Man and of the Carnivora, 



