140 THE FUNCTION 



in words, amount to his. f Dr. Prout conceives that a sort of 

 digestion is carried on in all parjs of the body, to jit for absorption 

 and future appropriation those matters that have been already assi- 

 milated." His chief reasons for this opinion are 1. That, if the 

 contents of the absorbents were really and wholly excrementitious, 

 they would be rejected, and not poured into the blood. 2. If they 

 are highly animalised, we have a reason for their admixture with 

 the crude chyle before it is poured into the blood. 3. The gra- 

 dual developement of the staminal principles of organised bodies, 

 by repeated organising processes, agrees with the general truth 

 of the operations of nature being never abrupt, but always slow 

 and gradual ; and matters already assimilated to the body must 

 be better adapted for its immediate use than the imperfectly as- 

 similated chyle. 4. Many animals can and do live for a con- 

 siderable time on their own bodies. 8 



I agree entirely in these reasons, and consider it a great mistake 

 to regard the lymph as a collection of excrementitious matters. 



f Blumenbach's words are, " Since the blood is a peculiar fluid, various 

 means are required to assimilate the foreign fluids which pass to the thoracic 

 duct. We must remember that a great part of the lymph has been derived from 

 the substance of the viscera and other soft parts formerly secreted from the blood, 

 and therefore already imbued with an animal nature." (Inst. Physiol., 446. 

 448.) Raspail also says, " Lymph is alcaline, and, in fact, to be considered as 

 a variety of chyle or colourless blood." p. 455. 



g Bridgewater Treatise. 



Dr. Magendie denied the existence of lymphatics in nearly all birds, but has 

 been amply refuted by Dr. Louth and many others. Birds have few lymphatic 

 ganglia ; and amphibia and fish still fewer ( Blumenbach's Manual of Comp. 

 Anat. translated, p. 174.) ; and invertebrate animals have no lymphatic vessels. 

 These, therefore, are considered a refinement of organisation, and lymphatic 

 ganglia a still greater. Professor Muller of Bonn has lately discovered in the 

 lymphatic system, under the skin of the frog, and several other amphibia, lymph- 

 hearts, pulsating regularly, though not simultaneously either with each other 

 or the blood-heart, and destined to advance the lymph in its vessels. Phil. 

 Trans. 1833. 



A short account of the first discovery of the absorbent system may be accept- 

 able at the close of this section. 



Hippocrates knew that the nutritive portion of the contents of the alimentary 

 canal was conveyed by certain vessels to the system. Erasistratus actually saw 

 the lacteals containing chyle aprwpiaf, yaXaKro? TrXp{f. From Galen we learn 



