196 The Blood-Supply of Lymphatic Vessels in Man 
induce him to study in this connection the lymphatics of other sub- 
cutaneous tissue and of the mesentery. In a second paper, 1883,° Dogiel 
noted the same “ perilymphatic ” plexus on the lymphatics of the capsule 
of the dog’s kidney, but failed to see them about the lymph channels of 
the periosteum or gall-bladder, failures which he attributed largely to 
imperfect injections. His papers, written about twenty-five years ago, 
form apparently the sole contribution to this subject.’ 
It is interesting to note that the structures which Dogiel described were 
not considered vasa vasorum solely because blood-vessels of a correspond- 
ing caliber possessed none! His theory of the significance of the encir- 
cling vessels was then of necessity far-fetched. “ Es ist vorliufig, un- 
moglich,” he says, “ eine stricte’ Antwort zu geben, aber denkbar wire es, 
dass bei praller Fiillung das Capillarnetz einen Druck auf das Lymphge- 
fass austibt und dadurch eine Fortbeweigung der Lymphe in der Richtung 
des geringeren Widerstandes begiinstigt.” Unfortunately he gives no 
measurement of the lymphatic vessels studied, but it is evident from his 
text and figures that they were rather the smaller lymphatics, though 
possessing muscle rings. The larger vessels, including the very largest, 
and the smallest ones had not been examined, nor is there any considera- 
tion of what changes occur in the type of circulation in ducts of differing 
caliber. 
In a study of the blood-vessels of the human small intestine, I was 
astonished to see the blood-supply to the lacteals, easily distinguished in 
small spread preparations of the mesentery. The minute plexus of capil- 
laries about these vessels was so distinct that it was easy to trace the 
course of the lacteal when the clearing agent had rendered its walls 
transparent. The investigation was merely a pleasant by-path, as it were, 
in the larger problem of the intestinal vessels. At the suggestion of 
Professor Mall, in view of the fact that it was possible to secure here 
an excellent demonstration of the lymphatic vasa vasorum, I have given 
a brief description of them as studied in the lacteals of man. The 
facts, however, seem of quite general significance, inasmuch as I have 
also examined in this connection lymphatics in the dog, the cat, and 
especially the sheep and goat. (In the sheep the collecting lacteals are 
*Dogiel, Alexander, Ueber die Beziehungen Zwischen Blut- und Lymph- 
gefassen. Arch. f. Mik. Anat., Bd. 22, 1883, p. 608. 
>Since this was written my attention has been called to the mention of 
blood vessels supplying the pleural lymphatics by Dr. W. S. Miller in the 
Proceedings of the Association of American Anatomists, Twenty-Second Ses- 
sion, March, 1907, Anatomical Record No. 4, this Journal—Vol. VI, No. 4. 
