342 GENERAL ANATOMY OF THE ABSORBENT SYSTEM. 



Whatever the facts may hereafter be found to be, in regard 

 to these researches of Treviranus for the high magnifying 

 powers employed would necessarily render him liable to opti- 

 cal illusions we are fully justified, at the present advanced 

 stage of anatomical science, in considering the absorbents 

 as not arising either from the arteries or veins, but as separate 

 vessels in the meshes of the cellular tissue, which divide, unite, 

 re-divide, and anastomose together again and again, till they 

 seem to occupy the whole mass of the tissue, and convert both 

 the proper cellular and serous membranes, into mere spongy 

 absorbing surfaces. 



It would seem that absorption took place in consequence of 

 the permeability of this net-work structure of the tissues to the 

 fluids in which the absorbents are bathed, (as has been so 

 clearly shown by E. Edwards* to be the case in the amphibiae,) 

 whether the fluid consists of effused serum, transmitted through 

 the pores of the blood-vessels and mixed up with the effete 

 molecules of the organs, or of ecchymosed blood, or of purulent 

 collections ; and that this permeation is aided by an attraction 

 through the walls of the vessels into their interior, called endos- 

 mosis by Dutrochet, where the fluid is placed under the 

 influence of the absorbents, and is passed onwards towards the 

 thoracic duct. If the assertions of Treviranus should be found 

 correct, it might be considered as being pumped up through a 

 series of the minutest capillary tubes. 



The contractility of the absorbent vessels is very evident, 

 and exists even for many hours after death, as may be seen 

 by opening an animal shortly after it has been killed. Their 

 force of resistance is also very considerable compared with 

 arteries and veins of the same diameter. In the inferior 

 extremities it is considered to be to that of the arteries in 

 the proportion nearly of 10 to 3. These vessels are very 

 elastic, and one which is almost imperceptible to the naked 

 eye, becomes, when fully distended with mercury, half a line 

 in diameter. 



* De 1'Influence des Agens Physiques sur la Vie, etc. 



