454 OF ABSORPTION AND SANGUIFICATION. 



In the afferent or peripheral f Fat, in maximum quantity (numerous fat or oil-globules). 

 Lacteals (from the Intes- I Albumen in medium quantity, 

 tines to the Mesenteric 1 Few or no Chyle-corpuscles, 

 glands). [ Fibrin almost entirely wanting. 



In the efferent or central f Fat, in medium quantity (fewer oil-globules). 

 Lacteals (from the Mes- J Albumen in maximum quantity. 



enteric glands to the 1 Chyle-corpuscles very numerous,but imperfectly developed. 

 Thoracic Duct). [ Fibrin in medium quantity. 



f Fat, in minimum quantity (fewer or no oil-globules). 

 m , . ,,. Albumen in medium quantity. 



j Chyle-corpuscles numerous, and more distinctly cellular. 

 [ Fibrin in maximum quantity. 



477. The aspect of the Lymph greatly differs from that of the Chyle, the former 

 being nearly transparent, while the latter is opaque or opalescent ; and this 

 difference is readily accounted for, when the assistance of the microscope is 

 sought, by the entire absence from the Lymph of that "molecular base" which 

 is so abundant in the Chyle. A considerable number of corpuscles are gene- 

 rally present in it; and these, like the chyle-corpuscles, correspond in all re- 

 spects with the colorless corpuscles of the Blood ( 145). Their amount, how- 

 ever, is extremely variable ; as is also that of the oil-globules, which sometimes 

 occur, whilst in other instances none can be discovered. Lymph coagulates like 

 chyle ; a colorless clot being formed, which incloses the greater part of the cor- 

 puscles. 



478. The fluid drawn from the Thoracic Duct, consisting as it does of an 

 admixture of Chyle and Lymph, will probably vary in its character and com- 

 position, according to the predominance of the former, or of the latter, of these 

 constituents. From some observations made by Bidder 1 on the quantity of 

 fluid discharged from the thoracic ducts of dogs and cats immediately after 

 death, it is inferred by him that the total amount of mingled lymph and chyle 

 which is daily poured into the circulating current, is equal in bulk to at least 

 two-thirds the entire mass of the blood ; though it furnishes, bulk for bulk, not 

 more than from one-fourth to one-third the quantity of solid matter which the 

 blood contains. It is difficult to suppose, however, that so large a quantity 

 really enters the circulating current through this channel, in addition to that 

 which is taken up by the veins ; and it is obvious that there are many circum- 

 stances which prevent the results of such observations from being fairly assumed 

 as furnishing an average for the entire day. 



479. The movement of the fluids taken up by the Absorbent vessels seems 

 to depend upon a combination of different agencies. The lower Vertebrata are 

 provided with "lymphatic hearts/ 7 or pulsatile cavities, by which important 

 assistance is given in the onward flow; but no such aid is afforded in Man or in 

 the Mammalia ; yet it is obvious that a considerable vis d tergo must exist, since, 

 if the thoracic duct be tied, it is speedily distended below the ligature, even to 

 bursting. The Absorbent vessels, like the veins, have a fibrous coat, into which 

 the muscular fibre-cells enter largely, and which is therefore contractile ; and it 

 has been found by Prof. Kblliker, that when the wire of an electro-magnetic 

 apparatus was applied to some well-filled lymphatics on the skin of a boy's foot, 

 soon after the removal of his leg by amputation, the stimulus occasioned a dimi- 

 nution in their diameter by at least one-half, and this not suddenly, but in the 

 course of between half a minute and a minute. 3 The same excellent observer 

 has observed that the lymphatic vessels in the tail of a Tadpole empty them- 

 selves by contraction after death, and then dilate again to their former size, just 

 as the smaller arteries do under the like circumstances; 9 and this fact is in ac- 



' " Mailer's Archiv.," 1845. 2 Kulliker and Siebold's Zeitschrift," 1849. 



3 " Annales des Sciences Naturelles," 1840, Zool., torn. vi. p. 99. 



