THE CORPUSCLES OF THE BLOOD 



99 



green tints the nuclei of the pale corpuscles, rendering counting easier. 

 The process of effecting the required dilution and placing it on the 

 slide is the same as that described for the red corpuscle. 



The pale may be counted at the same time as the red corpuscles if 

 Toison's or Sherrington's fluid is used. 



Leucocytosis. An increase in the number of pale corpuscles occurs 

 physiologically during digestion, especially after meals rich in proteins 

 and fat ; after muscular exercise ; in pregnant and parturient women ; 

 and in the new-born child. The neutrophil cells are increased in a 

 number of pathological conditions, in acute infections such as suppu- 

 ration, pneumonia, diphtheria, erysipelas, etc. In the condition known 

 as leukaemia, either the leucocytes or the lymphocytes may be greatly 

 increased, according as the marrow or lymph glands are the seat of 

 disease. Sometimes, although the total number is not much increased, 



Pro. 24. EMIGRATION OF LEUCOCYTES. (From Waller's "Human Physiology.") 



c'sals of the inferior surface of the frog's tongue as they appear after the escape 

 of the corpuscles, filled with stationary blood, deformed and indented at the 

 points of escape, near which the corpuscles are generally found. (After Waller, 

 Phil. Mag., 1846, "Microscopic Observations on the Perforation of the Capillaries 

 by the Corpuscles of the Blood.") 



the proportion of eosinophil corpuscles is increased. This occurs in 

 cases infected with the parasites trichina or anchylostomum, in asthma, 

 and certain skin diseases. 



Leucopenia occurs after exposure to X rays and injections of 

 cholin. In certain infections such as typhoid the pale corpuscles are 

 said to be diminished. 



Blood-Platelets. The so-called blood-platelets, or thrombocytes, 

 are bodies of doubtful origin. Opinions vary as to their character 

 and nature. According to one group of observers they are to be 



