A. W. Meyer 435 



in the mesentery and all its glands, in the thymus, in the axillae, also in the 

 breasts of infants" (p. 95). He spoke of this also in his letter of April 28, 1 652, to 

 "R. Morison, M.D., of Paris," in which he wrote: 



"But for various reasons, and led by several experiments, I could never be 

 brought to believe that that milky fluid [in the lacteals] was chyle conducted 

 hither from the intestines, and distributed to all parts of the body for their 

 nourishment; but that it was rather met with occasionally and by accident, 

 and proceeded from too ample a supply of nourishment and a peculiar vigour 

 of concoction; in virtue of the same law of nature, in short, as that by which 

 fat, marrow, semen, hair, etc., are produced; even as in the due digestion of 

 ulcers pus is formed, which the nearer it approaches to the consistency of milk, 

 viz., as it is -^vhiter, smoother, and more homogeneous, is held more laudable, 

 so that some of the ancients thought pus and milk were of the same nature, or 

 nearly allied. Wherefore, although there can be no question of the existence 

 of the vessels themselves, still I can by no means agree with Aselli in consider- 

 ing them as chyliferous vessels, and this especially for the reasons about to be 

 given, which lead me to a different conclusion. For the fluid contained in the 

 lacteal veins appears to me to be pure milk, such as is found in the lacteal veins 

 [the milk ducts] of the mammae. Now it does not seem to me very probable (and 

 more than it does to Auzotius in his letter to Pecquet) that the milk is chyle, and 

 thus that the whole body is nourished by means of milk. The reasons ^vhich 

 lead to a contrary conclusion, viz., that it is chyle, are not of such force as to 

 compel my assent. I should first desire to ha\e it demonstrated to me by the 

 clearest reasonings, and the guarantee of experiments, that the fluid contained 

 in these vessels was chyle, which, brought hither from the intestines, supplies 

 nourishment to the whole body. For unless we are agreed upon the first point, 

 any ulterior, any more operose, discussion of their nature, is in vain. But how 

 can these vessels serve as conduits for the whole of the chyle, or the nourishment 

 of the bodv, when we see that thev are different in different animals? In some 

 they proceed to the liver, in others to the porta only, and in others still to 

 neither of these. In some creatures they are seen to be extremely numerous in 

 the pancreas; in others the thymus is crowded with them; in a third class, again, 

 nothing can be seen of them in either of these organs. In some animals, indeed, 

 such chyliferous canals are nowhere to be discovered (vide Liceti Epist. xiii, lit. 

 ii, p. 83, et Sennerti Praxeos, lib. v, tit. 2, par. 3, cap. 1); neither do they exist in 

 any at all times. But the vessels which serve for nutrition must necessarily both 

 exist in all animals, and present themselves at all times; inasmuch as the waste 

 incurred by the ceaseless efflux of the spirits, and the wear and tear of the parts 

 of the body, can only be supplied by as ceaseless a restoration or niurition. 

 And then, their very slender calibre seems to render them not less inadequate 

 to this duty than their structure seems to unfit them for its performance: the 

 smaller channels ought plainly to end in larger ones, these in their turn in 

 channels larger still, and the whole to concentrate in one great trunk, which 



