LYMPHATIC SYSTEM OF £KIN AND MUCOUS MEMBRANES, 381 
vessels underneath the skin of the ear lobe and of the hind 
extremity of the rat, in the mesentery of the cat and the 
dog. 
3. In studying the lymphatics of the skin, it is necessary, 
as we shall show by-and-bye, to consider them in their 
relation to the various organs of which the skin consists, for 
they, viz. the lymphatics, as well as the blood-vessels, as 
shown by Tomsa, stand in a special relation to those organs. 
We shall then consider them as: A. The lymphatics of 
the connective-tissue matrix of the skin; B. those of the fat 
tissue ; c. those of the sweat glands; and pb. those of the 
hair-follicles, sebaceous glands and arrectores pili. 
Such an attempt of distinction has been made also by 
Neumann, but, as I shall show, what this observer described 
as the lymphatics of the fat tissue, hair-follicles, sebaceous 
glands, and sweat glands, are merely the lymphatics of the 
surrounding connective tissue, and do not in strictness bear 
any other relation to those organs than that of efferent vessels. 
The lymphatics that properly belong to those organs have not 
been known to Neumann or to his predecessors. 
The assertions of G. and F. Hoggan as to the non-existence 
of lymphatics in the fat tissue, hair-follicles, sebaceous glands, 
arrectores pill and sweat glands have, like most negative 
results, only a relative value, inasmuch as they show, what, 
however, did not require any special proof, viz. that whilst 
it is comparatively easy to demonstrate the lymphatics of the 
connective-tissue ground substance of the skin, those of the 
fat tissue and the glandular structures require special methods 
and attention. 
A.—The Lymphaties of the Connective-tissue Ground 
Substance. 
4, These are the lymphatics that have been known to all 
observers, and have been specially studied through injections 
with various colouring matters by Teichmann, Neumann, 
and others. They have been mentioned on the preceding 
page. Teichmann as well as Neumann (and also G. and 
F. Hoggan) consider the above lymphatics as the ultimate 
vessels and as not possessing any direct connection with the 
surrounding connective tissue. That they should have 
arrived at such a conclusion with reference to the con- 
nective tissue need not surprise us, seeing that they were 
not able to demonstrate the ultimate vessels belonging to 
the fat tissue or the glandular structures of the skin. 
5. The methods used by Teichmann and Neumann seem 
to be altogether unfavorable for the demonstration of the 
