880 DR. E, KLEIN. 
Royal Society,’ No. 182, p. 289") describe the lymphatics of 
the mammalian skin as consisting of a plexus of “ subepi- 
dermic” and one of ‘‘subhypodermic” vessels; both are 
connected by the “ dermic” vessels which form horizontal 
and vertical sets. 
All these authors agree that the superficial vessels are 
capillaries, while the deep ones are the efferent vessels 
possessed of valves, and G. and F. Hoggan consider also the 
** dermic ” vessels as possessed of valves. 
Both Teichmann and Neumann noticed lymphatics in the 
papille of the corium; they are branches of the superficial 
plexus. According to the former the papille of the hand 
and foot contain each a lymphatic vessel terminating in a 
cecal extremity, but always less superficially than the blood 
capillaries. Neumann saw in all well-formed papille either 
: single lymphatic terminating in a cecal extremity or a 
oop. 
G. and F. Hoggan deny the existence of these papillary 
lymphatics, but this is probably owing to their having 
studied only the skin of mammals, which generally do not 
possess well-formed papille. In well injected specimens of 
mammalian skin, however, indications of papillary lymphatics 
are undoubtedly present (see below). 
2. The lymphatic vessels referred to here and in the fol- 
lowing as the deep efferent vessels are distinct from, and 
much finer than the vessels which, being the collecting 
vessels of large cutaneous districts, run between the skin 
and the subjacent organs, as fascie, tendons, &c. These 
tubes are possessed of a comparatively thick wall, composed, 
besides the lining endothelium, of an elastic intima, a circular 
muscular media, and a thin connective-tissue adventitia. In 
this respect they conspicuously differ from the lymphatics 
belonging to the skin, whose wall is merely a single layer of 
endothelial plates, either more or less elongated with straight 
or sinuous outlines, as in the deep and larger, or sinuous in 
shape, as in the superficial smaller vessels. 
The collecting vessels possess, as shown by Biesiadecki, 
heir own system of blood-vessels, consisting of an arterial 
and venous branch, and a network of capillaries. 
A. Dogiel quite recently (‘Archiv f. Mikr. Anatom..,’ 
vol. xvii, p. 3359) demonstrated the existence of a network of 
blood capillaries surrounding the large efferent (collecting) 
1 T have not been able to find where the full paper of these authors is 
printed, and I am therefore limited to the “Abstract ’’ published in the 
‘Proceedings.’ Through the kindness of the authors I have learned quite 
recently (May, 1881) that their paper has been published in the ‘ Journal 
de l’Anatoniie et Physiologie,’ by Robin and Pouchet, Jan. and Feb., 1879. 
