196 EPITHELIAL GLOBULES. 



or contents of the lymphatic vessels, is a nearly colorless fluid, 

 resembling in appearance the serous fluid of a blister, and 

 S jp holding in suspension a large num- 



ber of white globules similar to 

 those of the blood. 



The lymph which is found in all 

 the lymphatic vessels, and the chyle^ 

 found only in that part of the lym- 

 phatic system belonging especially 

 to the digestive organ (see diges- 

 tion) are not two such different 

 fluids as one might suppose at first 

 sight, and as ancient physiologists 



Fig. GO. waramonje lym- considered them (lacteal vessels of 

 Aselli and Pecquet; serous vessels 

 of Olaiis Rudbeck). Both contain the same elements, and the 

 difference between them is of quantity only, not quality; the 

 difference is, besides, only momentary ; after digestion, or at 

 the moment when absorption takes place, the mesenteric lym- 

 phatic vessels (chyliferous) contain a larger quantity of the 

 absorbed elements, especially the fats ; we must also add 

 that in birds, owing to certain peculiarities in the mechanism 

 of absorption (Cl. Bernard), the difference between the con- 

 tents of the lymphatic vessels of the mesentery and those of 

 the other parts of the body seems to disappear. 



The quantity of lymph contained in the lymphatic vessels 

 (lymphatic cone, Fig. 60), and poured into the blood system, 

 varies greatly, according to the state of repose or activity of 

 the organs from which it proceeds ; * thus if a lymphatic fis- 

 tula be made in the neck of an animal, in order to obtain the 

 flow of lymph from the head, we observe that the fluid flows 

 much more abundantly during mastication, than during re- 



1 This is probably due to the fact that hy the activity of the 

 muscles the peri vascular spaces are alternately contracted and en- 

 larged, setting in motion the lymph towards the larger lymphatic 

 trunks. This current is further facilitated, or prevented fioin a 

 backward flow, by the valves placed all along the lymphatic vessels. 

 These valves are so arranged that, when thrown out, the fluid 

 passes in a direction from the periphery to the centre. [Am. ed.] 



* E, E, E, Epithelial surfaces, base of the lymphatic cone L, L, L ; this cone 

 is connected at its summit with the venous cone Vn. Art, Arterial cone. V, 

 Left Ventricle. V, Right ventricle. O, Left auricle. O', Right auricle. S P, 

 Pulmonary system. 



