OF THE BLOOD AM> C I K( T 



213 



the little molecules of the blood are seen in ceaseless motion 

 .'.live, but altogether without inherent activity, now borne 



forward as upon gentle waves, and then pushed more im- 



petuously along ; now advancing in serried ranks, now 

 ding their way in single files, the entire phenomena de- 

 ent upon the activity of the central organ. In the most 



minute intermediate vessels of all, a great degree of repose is 



Fig. 230. Portion of the lung of a live Triton drawn under the micro- 

 scope, and magnified 150 times; a, b, c, streams of venous blood; d, a 

 branch of the pulmonary artery. The very delicate capillaries serving as 

 bonds of union between the pulmonary vessels, are seen playing roum 1 

 little islets of the substance of the lung. The clear space between the 

 current of the blood and the walls of the vessels observed in the largei 

 branches is almost entirely wanting here. The lymph granules, therefore 

 are observed mixed with the general torrent. The arrows indicate th< 

 course of the currents. 



