202 The Blood-Supply of Lymphatic Vessels in Man 
little distance, with a regular succession of artery and vein. Such an 
arrangement, diagrammatically plain, is shown in the drawing of Fig. 4. 
Lacteals whose diameter is in the neighborhood of one-half a millimeter 
are often seen with a still further elaboration of the scheme of circulation 
shown in Fig. 2. The blood-supply, if bilateral, consists of a beautiful 
wide-meshed capillary net stretched on the two sides between the accom- 
panying vessels. Fig. 5 shows a typical instance of such a type of 
circulation. It is sometimes possible to observe a perfectly regular ar- 
rangement of these tiny arterioles and venules which have to do with 
the capillary mesh over the lymphatic. In a very few instances, I have 
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Fic. 6. Diagram illustrating supply of one-half of lacteal wall from one 
accompanying artery and drainage by opposite vein. 
Fic. 7. Diagram illustrating supply of either side of lacteal wall from both 
accompanying vessels. 
Fic. 8. Diagram illustrating accommodations to secure uniform capillary 
length in lypmhatics supplied from one or two sides. 
noticed that for some distance, one may find that the arterioles on one 
side of the lymphatic give capillaries only to one side and the venules 
there receive capillaries only from the other side. Also the points of 
origin of these small vessels from the long-accompanying stems may regu- 
larly alternate. The diagram of Fig. 6 will illustrate this. Such a type 
of circulation insures a separate capillary current on the two sides of the 
lymphatic and one which in general is in opposite directions on the two 
sides. The diagram shows a plan of circulation dependent on an almost 
exact equality of all arterial and venous stemlets. In reality such seldom 
occurs. Even with the irregularity caused by the occurrence now and 
then of larger or smaller arterioles and venules and the consequent unequal 
