GENERAL CONSIDERATIONS. 631 



The direction followed by the lymphatics in their course is nearly 

 always somewhat rectilinear ; they never show the flexuosities which are so 

 developed on the track of certain arteries, and even some veins. Neither do 

 they communicate with one another by transverse or arching anastomoses, 

 like those so commonly met with in the other two orders of canals belonging 

 to the circulatory apparatus. They frequently, however, in their parallel 

 course, bifurcate and join the neighbouring vessels. (At certain situations, as 

 at some of the articulations, and in other parts, the larger stems suddenly 

 break-up into a close interlacing plexus of small vessels or capillaries 

 (Fig. 295), which in their disposition, greatly resemble the rete mirahile of 

 the blood-vessels. This plexus is surrounded by condensed connective 

 tissue, and is penetrated by blood-vessels, though no communication takes 

 place between them and these, the only points at which communication occurs 

 being where the great lymphatic trunks empty themselves into the vena cava. 

 This rete would appear to be the first step towards the formation of a lymphatic 

 gland.) 



Fig. 295. 



A SECTION OF A SIMPLE RETE MIRABILE, VIEWED FROM THE SURFACE. 



a, a, Afferent vessels ; 6, 6, Efferent vessels only partially visible ; from the 



popliteal space. 



But of all the considerations relative to the course of these canals, the 

 most interesting are those which belong to the glandiform bodies placed 

 along their track, and whose abridged history we shall give immediately. 



TERMINATION. We have already mentioned the thoracic duct and the right 

 great lymphatic vein as being the receptacles of all the absorbent vessels of 

 the body, and we have also stated, that these two trunks enter the general 

 venous system ; this union of the sanguine with the lymphatic system takes 

 place at the origin of the anterior vena cava, and this vessel may be con- 

 sidered as the general confluent for all the absorbents. The researches of 

 Haller, Cruikshank, and Mascagni first threw light on this important fact ; 

 and it is to those of Fohmann, Panizza, Rossi, &c., that we owe the dedi- 

 cation of this discovery. 



