342 
Ez 
ANIMAL PHYSIOLOGY. 
phatic capillaries, which are, in essential points 
of structure, like the arterial capillaries; while 
the larger vessels may be compared to veins, 
though thinner, being provided with valves and 
having very numerous anastomoses. These 
lymphatic capillaries begin in spaces between 
the tissue-cells, from which they take up the 
effete lymph. It is interesting to note that 
there are also perivascular lymphatics, the ex- 
istence of which again shows how close is the 
relation between the blood vascular and lym- 
phatic systems, and as we would suppose, and 
as is actually found to be the case, between the 
contents of each. 
Lymph and Chyle.—If one compares the mes- 
entery in a kitten, when fasting, with the same 
part in an animal that was killed some hours 
after a full meal of milk, it may be seen that 
the formerly clear lines indicating the course of 
Fra. 283.—Valves ot the lymphatics and ending in glands have in 
lymphaties(Sappey). the latter case become whitish (hence their 
name, lacteals), owing to the absorption of the emulsified fat of 
the milk. 
Fic. 284.—Origin of lymphatics (after Landois). I. From central tendon of diaphragm of 
rabbit (semi-diagrammatic) ; s, lymph-canals communicating by X with lymphatic vessel 
re A, ie of lymphatic by union of lymph-canals; EZ, E, endothelium. II. Perivas- 
cular canal. 
