Report on the state of the blood and the blood-vessels in inflammation, and on other points relating to the circulation in the extreme vessels : together with a report on lymphatic hearts and on the propulsion of lymph from them, through a proper duct into their respective veins / by T. Wharton Jones.

Date:
1891
Catalogue details

Licence: Public Domain Mark

Credit: Report on the state of the blood and the blood-vessels in inflammation, and on other points relating to the circulation in the extreme vessels : together with a report on lymphatic hearts and on the propulsion of lymph from them, through a proper duct into their respective veins / by T. Wharton Jones. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    the facts and plienomena he is pretending to describe to his student-readers. The walls of the caudal vein of the eel are not endowed with rhythmical contractility, nor does the vessel pulsate. Though lymph is rhythmically propelled into it by the caudal lymph heart, the caudal vein is not distended to pulsation thereby, because the channel of tlie vein, like that of other veins, progressively increases in width in its course.* Besides this, the stream of lymph propelled into it by the caudal heart through its short narrow duct, is so small and so little forcible that even an equallv sized artery could scarcely be distended to pulsation by it. It is something deplorable that a student should be taught in his text-book, which he is expected to study and believe, under the terror of examination, that the vein in the tail of the eel which receives the lymph from the caudal heart serves the purpose of an accessory blood heart, whilst the caudal lymph heart itself is actually ignored. As to the veins in the wing of the bat, which are furnished with valves, though they are endow'ed with rhythmical contractility, and thereby serve as accessory blood hearts, they do not pulsate in the sense that an artery pulsates. In short, let it be repeated : the action of the veins of the bat’s wing is a heart-like action by which the flow of the blood is rhythmically accelerated in aid of the force of the heart of the general system from behind. The vein could not act like a heart and pulsate like an artery at the same moment. The pulse of an artery is synchronous with the contraction of the ventricle of the heart. No other example is as yet known, in any vertebrate animal, of veins cndoioed loith rhythmical contractility of their walls, and serving as accessory blood hcarts.'\ There being valves in the veins in the bat’s wing preventing regurgitation, the * Sec below, the section on l3’m])h hearts. f 1 have always considered it probable that in the very long tails of some animals, and even in our toes, the extreme veins might be endowed with rhythmical contractility of their wall, but in the few microscopical examinations I have been able to make, on the point, I have not discovered in the muscular walls characters similar to those presented by the muscular coat of the veins of the bat’s wing (§ 92).