Or THE BLOOD AND CIRCULATION. 



(fig. 229). In these vessels the round lymph-corpuscles 

 (a, a, a, a) are seen swimming under, over, and behind the oval 



blood-discs (&, b), 

 both of them pro- 

 ceeding paripassu 

 here, and having 

 the same mode- 

 rated motion : still 

 it is impossible not 

 to observe that the 

 blood-corpuscles 

 are possessed of a 

 greater degree of 

 lubricity, that they 

 evidently glide 

 * more readily over 

 one another and 

 over the smooth 

 walls of the ves- 

 sels, than the 

 lymph-corpuscles, 

 which seem often 

 to get set fast at 

 the bendings of 



the vessels, and at 



Fig. 229. View m outline of a large vein of the 

 frog's foot magnified 600 times. The blood-glo- 

 bules, I and c, present sometimes their thin edges, the angles where 

 sometimes their broad surfaces, here they lie pa- anastomosing 

 rallel, there diagonally, and elsewhere athwart the 

 course of the vessel. The lymph-globules, a, a, are 

 principally conspicuous in the clear space near the 

 walls of the vessel. 



branches are re- 

 ceived or given 

 off ; there they re- 

 main sticking for 

 in instant, and then are suddenly carried on again. Single 

 olood-corpuscles, too, may frequently be observed hurled 

 by a wave, as it were, against angles of the containing 

 vessels, and remain hanging for a brief interval ; at these 

 times they may be seen quivering or oscillating, in spite 

 of the pressure they must undergo ; but their stoppages 

 are never long, they soon fly off again, or, becoming in- 

 volved in the general stream, they are borne onwards. In 

 contemplating the circulation under these circumstances, a 

 spectacle of the most interesting kind is presented to the eye : 



