LYMPHATIC AND LACTEAL SYSTEM. 



221 



The lymph is said to coagulate more readily 

 after passing through the lymphatic glands, and 

 the nearer it approaches the thoracic duct. I 

 have not found this to be the case in so marked 

 a degree as has been stated. I have collected 

 lymph from the lymphatics of the intestines 

 before they reached the glands, and from va- 

 rious parts of the body in which no glands are 

 situated, and have invariably found the fluid to 

 coagulate spontaneously, although if in small 

 quantity it may shortly return to the liquid 

 state. 



The fluid contained in the lacteal vessels in 

 Mammalia is of a white colour like milk, and 

 is called chyle ; it has a marked saline taste, is 

 slightly alkaline, and has no perceptible odour. 

 I have now before me several specimens of 

 recent chyle collected carefully from the lacteal 

 vessels, before they reach the glands, from the 

 glands themselves, from the vasa efterentia of 

 the glands, and from the thoracic duct. These 

 specimens were taken from a donkey killed for 

 the purpose, seven hours after a full meul of oats 

 and beans. About half a drachm was obtained 

 from the vasa inferentia, and a drachm from the 

 mesenteric glands themselves in watch-glasses; 

 from the vasa efferenlia about three drachms 

 were procured in a test-tube, and from the 

 thoracic duct in a phial nearly an ounce. All 

 were of a pure milk-white colour except that 

 from the thoracic duct, which had a slight pink 

 tint. They all jellied spontaneously in from 

 five to ten minutes; that from the vasa infe- 

 rentia again liquified in about half an hour, 

 and remained in this state ; on other occasions 

 I have known it retain its solidity. I have also 

 seen the chyle from the glands, and from the 

 vasa efferentia, return to the liquid state after 

 having been coagulated for a short period. I 

 have observed the same occurrence in lymph 

 before and after it had traversed a gland. In 

 about half an hour, with the exception already 

 noticed, these specimens of chyle separated 

 into a kind of serum and clot, the latter form- 

 ing by far the greater portion, at least four-fifths 

 of the whole. This clot, however, on being 

 broken up and pressed, contracted to one- 

 twentieth part of its former bulk; both the 

 serum and the clot retaining their white colour. 

 In the specimen obtained from the thoracic 

 duct the pink tint was confined to the clot, and 

 the serum was whitish or whey-coloured. It 

 ought here to be stated that chyle, before it has 

 reached the receptaculum, will not always se- 

 parate into a fluid and solid portion, but will 

 remain of the consistency of a soft white jelly, 

 from which, however, by breaking it up, a white 

 fluid may be obtained. 



I find great error and confusion in the 

 descriptions hitherto given of the microsco- 

 pical appearances of the chyle. Miiller and 

 Breschet both state, that the white colour of 

 the chyle depends upon its globules, which 

 they then proceed to describe; they both 

 quote Prevost and Dumas as estimating the 

 diameter of the chyle globule at l-7199th of 

 an inch, or about half that of the blood glo- 

 bule in man. Miiller says that in the cat he 

 finds them of the same size as the blood cor- 



puscules, and in the rabbit some of them were 

 larger ; in the calf, the dog, and the goat he 

 found them much smaller than the blood cor- 

 puscules of the same animal. Breschet, in his 

 work on the lymphatic system, published in 

 1836, acknowledges the unsatisfactory state of 

 our knowledge with respect to the globules of 

 the chyle and lymph. Tiedemann and Gmelin, 

 in their elaborate work on digestion, distinctly 

 state they consider the white colour of the chyle 

 to depend upon fatty particles, which form a sort 

 of emulsion with the serous portion of the 

 chyle. Mr. Gulliver has given by far the most 

 correct description of the microscopical appear- 

 ances of the chyle that I have met with ; he is 

 the first who has noticed the extremely minute 

 particles which constitute the characteristic 

 microscopical appearance of the chyle, for the 

 larger globules, noticed by most observers, are 

 found also in the lymph. Mr. Gulliver has not, 

 however, corrected the statement of Miiller, Bre- 

 schet, and others that the white colour of the 

 chyle depends upon these larger globules; but 

 I doubt not he would acquiesce with me in 

 opinion that the white colour depends alto- 

 gether upon the more minute particles. With 

 these preliminary remarks I shall proceed to 

 describe the microscopic characters of the chyle 

 from my own obervations. 



Every one is aware that the lacteals, when 

 not conveying chyle, contain a transparent 

 fluid not to be distinguished by the eye from 

 the lymph of other parts of the system; to 

 this fluid is added, during the digestion of 

 a meal, myriads of extremely minute parti- 

 cles, twenty or thirty times less in size than 

 the lymph or blood globules of the same 

 animal, and which can scarcely be distin- 

 guished by a glass of less power than one- 

 eighth of an inch focus, upon which un- 

 doubtedly the white colour of the chyle de- 

 pends; when these particles are very numerous, 

 the chyle is perfectly white and opaque ; when 

 less so, it will be whey-coloured or semitrans- 

 parent. These particles are peculiar to the 

 chyle, and I have been in the habit, for the 

 last two years, of calling them the chyle gra- 

 nules, in contradistinction to the globules of 

 different kinds which are also found in this 

 fluid. The chyle granules, when allowed to 

 dry on a piece of glass, measure from l-20,000th 

 to l-10,000th of an inch in diameter, and are 

 larger and more distinct in carnivorous than in 

 graminivorous animals. The most remarkable 

 peculiarity, which I believe I am the first to 

 notice, of these chyle granules, is their con- 

 tinual vibratory or oscillatory motions. On 

 viewing under the microscope a drop of chyle 

 taken from the lacteal of a carnivorous animal, 

 and placed between a piece of glass and 

 talc, the motions of the chyle granules 

 will be seen to be so constant and ceaseless 

 that the observer would at first sight be led to 

 consider the chyle as a moving mass of restless 

 animalcules; but on noticing the limited ran^e 

 as well as the sameness, and apparent wantof 

 object, in these to and fro movements, he will 

 probably feel inclined to attribute them to 

 some unknown attraction and repulsion, influ- 



