LYMPHATIC AND LACTEAL SYSTEM. 



219 



is much larger than that of the branches of the 

 vasa afferentia and efferentia, a fact that has 

 been too much overlooked by anatomists, and 

 which leads me to conjecture that these vessels 

 enter and arise from its convolutions by open 

 mouths; be this as it may, we know that the 

 injection conveyed into the gland by the vasa 

 afterentia readily passes from it by the vaso 

 efferentia. I should not here omit to mention 

 a circumstance already adverted to of consi- 

 derable interest, viz. that the injection conveyed 

 to a gland by an afferent vessel is occasionally 

 received by the veins of that gland, and to all 

 appearance without rupture or extravasation. 

 The occurrence itself is admitted by all ; but 

 physiologists differ much in their explanations 

 of the channel by which the injection has en- 

 tered the vein. Some explain it by an extrava- 

 sation into the cellular tissue from an injury 

 by which both sets of vessels have been opened ; 

 others, who conceive that a minute net-work of 

 lymphatics exists on the interior of the veins 

 and arteries, will have no difficulty in ima- 

 gining a rupture of this net-work; the vasa 

 vasorum of the lymphatics, which may be dis- 

 tinctly seen on their interior after a minute in- 

 jection, may be supposed to have given way 

 and to have admitted the injection from the 

 interior of the lymphatics. But these opinions 

 will not explain why this communication 

 should take place within the gland only, and 

 invariably with the vein, never with the artery. 

 The general opinion is that this communi- 

 cation takes place accidentally, and not by 

 any real continuity of canal. Fohmann stands 

 almost alone in asserting that a natural commu- 

 nication does exist between the lymphatics and 

 veins within the glands, especially in those 

 situations where in birds, reptiles, and fishes, 

 the lymphatics have been proved to terminate 

 directly in the veins. Fohmann even ventures 

 an opinion as to the mode in which the lym- 

 phatic joins the vein ; not, he conceives, by con- 

 tinuity of peripheral branches, but by an effer- 

 ent lymphatic opening into the side of a vein 

 before the latter emerges from the gland. 

 Without committing myself to the exact mode 

 of union, I must confess I agree with Fohmann 

 that a natural communication does exist in 

 some of the glands between the lymphatics and 

 the veins. It has been observed hundreds of 

 times. It has occurred to every anatomist who 

 has engaged himself with the injection of these 

 vessels ; I have met with at least twenty such 

 instances myself, while a similar communica- 

 tion between a lymphatic and artery within a 

 gland has never been observed. I am entirely 

 at a loss, therefore, to account for these occur- 

 rences without admitting a natural channel to 

 exist between the one set of vessels and the other. 

 I have before observed that the exact arrange- 

 ment of the bloodvessels in the interior of the 

 canals of which the glands are constituted, is 

 not known ; but we are equally in the dark with 

 respect to the vascular supply received by other 

 minute tubes, such as the seminiferous, urini- 

 ferous, and lactiferous tubes, from the capilla- 

 ries of whose lining membranes, however, we 

 admit that their appropriate secretions are de- 



rived. As far, then, as organisation is con- 

 cerned, there is nothing to forbid our ascribing 

 a secreting function to the interior of the 

 canals of the lymphatic glands, or of the lym- 

 phatic vessels generally. There can be little 

 doubt but that the lymph and chyle undergo 

 modifications in their passage through the ab- 

 sorbent glands, although we are not at present 

 prepared to state the nature of that modification. 

 It has been observed that the chyle included 

 between two ligatures in its own vessel before 

 it has reached a gland will not coagulate, 

 although after it has passed the gland coagula- 

 tion readily takes place. Miiller remarks 

 from this circumstance that the glands of the 

 mesentery appear to have the power of changing 

 part of the albumen of the chyle into fibrin. 

 At any rate we are warranted, from the little we 

 do know of the structure of the absorbent gland, 

 in asserting, that the chyle and lymph collected 

 from various sources must be mingled together 

 in the glands, that they must be divided into 

 extremely minute streams on their entrance 

 into or exit from a gland, that they must be 

 submitted to a great extent of surface of their 

 containing vessels, and subjected to considera- 

 ble delay in their passage through the gland. 

 Mr. Gulliver's observations on the fluid con- 

 tained in the absorbent glands would almost 

 lead us to conclude that their proper office was 

 to fabricate the peculiar globule of the lymph 

 and chyle ; my own observations on these fluids 

 before and after reaching the glands would 

 not bear out this opinion ; but as I have next 

 to consider the characters, physical, microsco- 

 pical, and chemical, of these fluids, I shall 

 shortly enter more fully into this subject. 



Lymph is a transparent fluid, slihtly opa- 

 line, of a light straw colour; its specific gravity 

 is 1022-28, water being lOOO'OO; its odour, 

 which is slight, varies, and is peculiar to each 

 animal ; it is alkaline, and has a saline taste. I 

 collected in an ounce-phial about three drachms 

 of lymph from a large lymphatic in the axilla 

 of a horse, by inserting a small silver tube into 

 it. In about ten minutes the whole had coa- 

 gulated into a jelly-like mass ; in half an hour 

 a separation had taken place into a fluid and 

 solid part : the latter formed a soft tremulous 

 clot modelled to the form of the phial. A 

 drop of this lymph placed on a piece of glass, 

 and covered by talc, was submitted to inspec- 

 tion under the microscope, immediately after its 

 removal from the vessel. A number of colourless 

 spherical globules were observed in it having a 

 granular surface, and precisely resembling those 

 described by Mr. Gulliver as belonging to the 

 mesenteric, lymphatic, and thymus glands. I 

 am not aware whether Mr. Gulliver considers 

 these globules as belonging exclusively to the 

 glands, or whether he thinks them distinct 

 from or identical with the lymph and chyle 

 globule. My own observations lead me to 

 state that they are found in the lymph or chyle 

 before and after passing the glands, as well as 

 in their transit through them. I am also dis- 

 posed to assert that these globules remain co- 

 lourless, and that whenever the lymph possesses 

 a slightly red tint, it obtains that tint from the 



