LYMPHATIC SYSTEM OF SKIN AND MUCOUS MEMBRANES, 389 
the plexuses of lymphatics are not uniform, being limited 
to the connective tissue separating or surrounding these 
groups. 
The septa of the adipose tissue possess fewer interlobular 
lymphatics than in man. 
21. In what connection do the above lymphatics stand to 
the blood vessels? Both in the skinof manand mammals, 
but more especially in the former, I find in all strata of the 
corium, notably in the middle strata, some lymphatic vessels 
entering a more or less intimate relation with the blood- 
vessels ; this consists in the following :—(a) We find a blood- 
vessel, either an arterial or venous branch, ascending to, or 
descending respectively from the surface of the corium 
accompanied for a longer or shorter distance on one or both 
sides by one or two lymphatic vessels ; or (2) the blood vessel 
is crossed by one or two or even more small lymphatics in a 
very oblique direction, and the latter appear at this point as 
if belonging to the sheath of the former. Around the larger 
arterial branches we find numerous smaller and_ larger 
lymphatics which, in some instances, form a more or less 
complete sheath around the blood-vessel, perivascular lym- 
phaties. 
22. In what relation do the lymphatics stand to the 
general connective-tissue matrix, or with other words, what 
is the nature of the lymphatic rootlets? Bricke, Ludwig, 
v. Recklinghausen were the first who maintained the origin 
of the lymphatics in the clefts of the connective tissue. 
These clefts, situated between the bundles or groups of 
bundies of the connective-tissue, have been injected in many 
organs naturally and artificially, and have been shown to be 
connected with the lymphatics. Without regarding it neces- 
sary to enter into a detailed historical review of this question, 
I will only mention the researches of v. Recklinghausen, 
Key, and Retzius, of Sikorsky, myself, Arnold, Sachs, 
Kiittner, and others, by which it has been conclusively estab- 
lished that the interfascicular spaces, 7.e. the clefts and 
channels between the bundles and groups of bundles of con- 
nective-tissue fibrils, containing in a semi-fluid interstitial 
albuminous substance the flattened connective-tissue cells, 
are the paths through which the normal current of plasma, 
irrigating the connective tissue, proceeds, and that through 
this current fluid as well as formed material is carried 
into the lymphatics. How is this, then, effected? How are 
the interfascicular clefts and spaces connected with the 
lymphatics ? 
As I have pointed out in my ‘ Anatomy of the Lymphatic 
