84 A Manual of Veterinary Physiology. 



blood in the proportion of 1 to 335 of red (Landois and 

 Stirling), but vary in their proportion according to the vessel 

 from which the blood is examined. In the splenic artery 

 there are very few, in the splenic vein they are exceedingly 

 numerous. Blood which has been removed from the vessels 

 contains but few, for the reason that they are probably 

 broken down during the formation of fibrin. The white 

 corpuscle is much larger than the red, and consists of what 

 is known as protoplasm, which is granular in appearance ; 

 it possesses a nucleus or nuclei, and is endowed with move- 

 ment ; there is no cell- wall or envelope, but the body is 

 made up of delicate fibrils, and the nucleus the same. 



The movements, known as amoeboid, exhibited by these 

 corpuscles are remarkable, they are shown by changes of 

 form, projections shooting out from the surface and being 

 again retracted. The corpuscle has also the power of taking 

 up small particles of colouring matter, bacteria, etc., into 

 its interior. The amoeboid movement is destroyed by heat, 

 and by shocks from an induction coil. 



The white corpuscles contain about 10 per cent, of 

 solids, which consist of serum globulin, serum albumin, 

 and myosin, or its precursor, myosinogen, as myosin pro- 

 bably only occurs after death. Another nitrogenous prin- 

 ciple is nuclein, which is largely found in the corpuscle ; it 

 is remarkable for containing phosphorus. Besides these 

 we have the complex fatty body lecithin, cholesterin, 

 glycogen (especially in the horse), and salts, the latter 

 principally phosphates probably derived from the phos- 

 phorus containing compounds. 



The origin of the white corpuscles is from the lymphatic 

 system, by which they enter the blood stream through the 

 large lymphatic channels opening into the vena cava at the 

 junction of the two jugular veins. The white corpuscles, as 

 well as the red, are constantly being used up and as con- 

 stantly replaced. This using up consists in the power they 

 possess of passing through the walls of the vessels into the 

 surrounding tissues, from which they are removed by the 

 lymph channels, and so find their way back to the blood. 



