402 DR. E. KLEIN. 
large and fine lymphatics running from the dorsum of the 
tongue towards the base of the epiglottis. The vessels 
anastomose under acute angles, and increase in size as they 
approach the epiglottis ; their valves are very conspicuous. 
Sappey already injected the dense network of the lym- 
phatics of the mucous membrane of the gums and soft palate 
and tongue. 
39. Examining a successfully injected and hardened lip, 
palate, or mucous membrane of pharynx in vertical and hori- 
zontal sections under the microscope, it will be seen that the 
lymphatics are present in and extend through all parts of the 
mucous membrane more or less uniformly from the epithe- 
lium of the surface down to the deep tissue that contains the 
glands, fat, muscle, &c. The vessels are connected every- 
where in plexuses, but there are in the superficial parts a 
good many vessels that appear to terminate freely in the 
tissue (see below). 
Many vessels run in a horizontal direction, and they can 
be, therefore, better seen in horizontal than in vertical sec- 
tions. Those belonging to the superficial parts of the mucous 
membrane are fine as compared with those of the deeper 
parts, and they run a more or less straight or wavy course. 
Everywhere the papille possess their own lymphatics in the 
form of single or compound loops connected with the super- 
ficial lymphatics. They penetrate more than half or two 
thirds into the tissue of the papille. These papillary lym- 
phatics are best seen in the human lip and soft palate, owing 
to the very great length of the papillz, but they are present 
also in those of other parts in man, dog, and rabbit. The 
lymphatics of the deeper parts are distinctly possessed of 
valves ; such valves are not easily seen in the more super- 
ficially seated lymphatics, although in some isolated instances 
there are indications of their presence in the shape of saccular 
dilatations of the vessel. 
The wall of the lymphatics of the superficial layers is 
irregular in its outline, being apparently possessed of more 
or less numerous pointed processes (see below). 
The lymphatics of the loose submucous tissue ate con- 
siderably larger and possessed of valves; they communicate 
freely with the plexus of the large lymphatics of the muscles 
and the fat tissue. 
40. The relation between the lymphatics of the mucous 
membrane and the interfascicular lymph-spaces of the con- 
ncctive-tissue ground substance is a very intimate one, and 
is exactly the same as that described in the connective tissue 
of the skin, and it is, therefore, unnecessary to again minutely 
