IM 



JiOOK V. 



( 'umiLATouY APPARATUS. 

 THK animal economy is incessantly traversed by two fluids U<l und 



The blood is a liquid, coloured bright-red or brown by particular globules, 

 from which the tissues derive not only the materials for nutrition and 

 secretion, but also the exciting principle which vivifies the organic 

 matter. It is named red or dark-coloured blood, according to its 

 tint. 



The lymph or wliite blood is a transparent, citrine-coloured fluid, which 

 can bo obtained from the majority of the organs. That which comes from 

 the abdominal portion of the alimentary canal is charged, during digestion, 

 with a portion of the reparative materials elaborated in that apparatus, and 

 is distinguished by its lactescent aspect ; it is designated the chyle. 



Fig. 2:,7. 



TIIKOItKTICAL PLAN O* THE CIRCCLATOK V SYSTEM. 



(if, D, c, E, The canal for red blood; K, it, A, a, Cannl for black blood. The arrow- 

 indicate the course of the blood. The two canals an- iv]>n'-rntfd in their middle 

 portion, AH, CD, as isolated; but in nattuv they arc enveloped at this point in a 

 common sac that concurs to form the heart.) 



f 



These fluids are Carried by vessels tubes which are continuous with one 

 another. When joined together, end to end, these tubes give rise to three 

 principal canals : 



"One of these canals extends from the lungs to all parts of the body, 

 and is traversed by red blood. 



