THE FLUIDS OF THE BODY 83 



There must be something in the condition of worn-out red 

 corpuscles which either makes them peculiarly attractive to 

 predatory leucocytes or renders them an exceptionally easy 

 prey. It does not require much imagination to picture the 

 drama which is enacted in the spleen. Slow-moving leuco- 

 cytes are feeling for their food. The majority of red cor- 

 puscles pass by them ; a few are held back. The leucocytes, 

 like children in a cake-shop, cannot consume all the buns. 

 A selection must be made, and preference is given to the 

 sticky, sugary ones. Red corpuscles when out of order show 

 a tendency to stick together. When blood is stagnating in 

 a vein, or lying on a glass slide in a layer thin enough for 

 microscopic examination, its red discs are seen after a time to 

 adhere together in rouleaux. The parable of a child in a cake- 

 shop is not so fanciful as it may appear. 



The differentiation of function of organs is not as sharp as 

 was formerly supposed. Evidence of their interdependence 

 is rapidly accumulating. The activity of various organs is 

 known to result in the formation of by-products termed 

 " internal secretions," which influence the activity of other 

 organs, or even of the body as a whole. The spleen enlarges 

 after meals. This may be merely connected with the en- 

 gorgement of the abdominal viscera which occurs during active 

 digestion, or it may indicate, as some physiologists hold, that 

 an internal secretion of the spleen aids the pancreas in pre- 

 paring its ferments. The spleen enlarges greatly in ague and 

 in some other diseases of microbial origin. This has been 

 regarded as evidence that it takes some part in protecting the 

 body against microbes. But whatever may be the accessory 

 functions which it exercises, they are not of material import- 

 ance to the organism as a whole, seeing that removal of the 

 spleen causes no permanent inconvenience either to men or 

 animals. Its blood-destroying functions are taken on by 

 accessory spleens, if there be any, and by lymphatic glands. 

 The marrow of bone also becomes redder and more active. 

 Under certain circumstances, red corpuscles, or fragments of 

 red corpuscles, are to be seen within liver-cells ; but it is 

 uncertain whether blood-destruction is a standing function of 

 the liver. 



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