CIRCULATION OF THE BLOOD. 



131 



etc.). We may thus conclude, with Germain See (" Pathologie 

 Experimental : " Anemies), that, as a general rule in diseases, espe- 

 cially where there is anaemia, there is really neither an excess or a want 

 of fibrine, but the plasmine is more or less perfect, that is, more or 

 less easily divided into two elements, thus partaking of its nature 

 in different degrees. Finally, according to Vulpian, all the albu- 

 minous parts of the blood form probably a composition, two parts of 

 which, serine and plasmine (with its two elements) are the result 

 of a division, as alcohol and carbonic acid are produced in the 

 analysis of sugar. This explanation throws fresh light on the 

 pathogeny of albuminuria, especially of that sort caused by changes 

 in the albumen of the blood, and of albuminuria occurring after 

 the artificial ingestion or injection of albumen, even of albumen 

 taken previously from the blood of the animal. (Experiment of 

 Cl. Bernard, of Stokvis, of Calmettes.) 



CIRCULATION OF THE BLOOD. 



The circulation consists of the continued movement of the 

 blood in a circular reservoir formed of ramified tubes (circu- 

 latory apparatus). This 

 apparatus, looked at as 

 a whole, is simply a series 

 of tubes, with different 

 functions and properties 

 (Fig. 37). These are: 

 K The heart, a muscu- 

 lar reservoir, divided 

 into four cavities (in 

 man, but more simple 

 in the lower animals). 

 At first it also forms a 

 cylindrical tube, which 

 during the life of the 

 embryo becomes twisted, 

 and is divided so as to 

 form the auricles and 

 the ventricles. 2. The 

 arteries, a system of 

 ramified tubes, in the 

 shape of a tree, espe- 

 cially remarkable for the 

 thickness and strength of their coats (Fig. 37, a). 3. The 

 veins, another system ramified like that of the arteries, but 



Fig. 37. Plan of the circulating system < 



* C R, Heart, ventricle (o, auricle; s, ., valves). a } Arterk-s. CP, Capil 

 laries. />, Veins. The arrows show the direction in which the liquid flows. 



