146 HANDBOOK OF PHYSIOLOGY. 



per cubic millimetre, on the second to fourth day from 8,700 to 12,400, 

 and after the fourth day from 12,400 to 14,800. 



Varieties. The colorless corpuscles present greater diversities of 

 form than the red ones. They are usually classified according to their 

 reaction to staining agents, or to the presence or absence of granules in 

 their cytoplasm. Kanthack and Hardy offer the following classification 

 based upon both phenomena: 



s ( 1. Finely granular. 



A. Oxyphil (staining with acid dyes). ^ 2 Coar g ely granu lar. 



B. Basophil (staining with basic dyes). 1, Finely granular. 



( 1. Small. 



C. Hyaline - ( 2i Large. 



The finely granular wyplul constitutes 75 per cent of all leucocytes. 



It has an average diameter of 10,u, and possesses phagocytic action to a 



marked degree that is, it possesses the power of ingesting foreign par- 



A B tides. Its nucleus consists of several 



lobes united by threads of chromatin. 

 This cell was formerly known under 

 the term neutrophil, because of its sup- 

 posed reaction to neutral dyes. 



The coarsely granular form or eo- 



i fi . *,... Three colored blood-cor- t j J 



puscles. B. Three colorless blood-cor- sinOpllll Constitutes Only 2 per Cent 



puscles acted on by acetic acid: the 



nuclei are very clearly visible. X 900. O f the leucocytes. It has a diameter 



of 12/i and a reniform nucleus. 



The Ijasoplnl cell is rarely found in normal blood. It may occur oc- 

 casionally during periods of digestion. It is a small, spherical cell, 

 with an irregular nucleus and a diameter of ?/-*. 



The small hyaline leucocyte is also called a lymphocyte, because of the 

 large numbers found in adenoid tissue, and is supposed to be an imma- 

 ture form. The nucleus is proportionately large, and is surrounded by 

 but little protoplasm in which no granules can be detected. The cell is 

 about the size of a red blood cell, and constitutes from 10 to 20 per cent 

 of all leucocytes. 



'The large hyaline or myelocyte varies in diameter from 8.5 to 10,u. Its 

 nucleus is spherical or reniform, and is surrounded by more protoplasm 

 than in the case of the lymphocyte. It forms about 10 per cent of the 

 leucocytes. 



Amoeboid Movement. The remarkable property of the colorless 

 corpuscles of spontaneously changing their shape was first demonstrated 

 by Wharton Jones in the blood of the skate. If a drop of blood be ex- 

 amined with a high power of the microscope, under conditions by which 

 loss of moisture is prevented, and at the same time the temperature is 

 maintained at about that of the body, 37 C. (98.5 P.), the colorless 



