Note bbb — BOOK IV.

There are too many Particulars to be insisted on, observable in the Passages of the Chyle, from the Guts to the Left Subclavian Vein, where it enters into the Blood; and therefore I shall only, for a Sample of this admirable Oeconomy, take notice of some of the main and more general Matters. And,

1. After the Food is become Chyle, and gotten into the Guts, it is an excellent Provision made, not only for its Passage through the Guts, but also for its Protrusion into the Lacteals, by the Peristaltick Motion and Valvulæ conniventes of the Guts. 2. It is an admirable Provision, that the Mouths of the Lacteals, and indeed the Lacteals primi generis themselves are small and fine, not wider than the Capillary Arteries are, lest by admitting Particles of the Nourishment grosser than the Capillaries, dangerous Obstructions might be thereby produced. 3. After the Reception of the Aliment into the Lacteals primi generis, it is a noble Provision for the Advancement of its Motion, that in the Mesenterick Glands, it meets with some of the Lymphæ-Ducts, and receives the Impregnations of the Lympha. And passing on from thence, it is no less Advantage. 4. That the Lacteals, and Lymphæ-Ducts meet in the Receptaculum Chyli, where the Aliment meeting with more of the Lympha, is made of a due Consistence, and Temperament, for its farther Advancement through the Thoracick Duct, and so into the Left Subclavian Vein and Blood. Lastly, This Thoracick Duct it self is a Part of great Consideration. For (as Mr. Cowper saith) If we consider in this Duct its several Divisions and Inosculations, its numerous Valves looking from below upwards, its advantagious Situation between the great Artery and Vertebræ of the Back, together with the Ducts discharging their refluent Lympha from the Lungs, and other neighbouring Parts, we shall find all conduce to demonstrate the utmost Art of Nature used in furthering the steep and perpendicular Ascent of the Chyle. Anat. Introduct.