DIGESTION OF FOOD. 
not yet so fully known—possibly by a simi- 
lar inceptive process; nor is it ascertained 
what constructive or other chemical pro- 
cesses they may perform; though it is not 
at all likely that the work of the amceboid 
cells is confined to the transport of fat 
alone, but that other matters are also thus 
removed inward to the lacteal. 
Experimental.—_If two frogs under the 
influence of urari, to remove the effect of 
muscular movements, be placed under ob- 
servation, the one having its brain and 
spinal cord destroyed, the other intact, in 
both the aorta divided across, and normal 
saline solution injected into the posterior 
lymph-sac (beneath the skin of the back), 
it will be found, on suspending the two 
by the lower jaw, that, in the frog with 
the nerve-centers uninjured, abundance 
of saline fluid is taken up from the dor- 
sal sac and expelled through the aorta, 
347 
WN 
Wiss 
a) 
48) 
Aas 
a 
eee 
i 
; eC a eg 
Fie. 291.—Intestinal villus 
pe ere a, a, a, 
epithelial covering ;_b, 
b, eapinery network ; 
ce, c, longitudinal mus- 
cular fibers ; d, lacteal. 
but in the other case none, the heart remaining all but empty. 
Bie. 292.—A. Villi of man, showing blood-vessels and lacteals; B. Villus of sheep (after 
Chauveau). 
