256 TEXT-BOOK OF PHYSIOLOGY 



spicuous and sharply defined. From its structure it is apparent that the 

 white corpuscle belongs to the group of undifferentiated tissues and resembles 

 the cells of the embryo in its earliest stages as well as the unicellular organism, 

 the amoeba. 



Chemic Composition. The chemic composition of the white corpuscles 

 has been inferred from an analysis of pus-corpuscles, with which they are 

 practically identical, and of lymph-corpuscles from the lymph-glands. Of 

 the corpuscle about 90 per cent, is water and the remainder solid matter 

 consisting mainly of proteins, of which nuclein, nucleo-albumin, and cell 

 globulin are the most abundant. The two former are characterized by the 

 presence of a considerable quantity of phosphorus, amounting to as much as 

 10 per cent. Lecithin, fat, glycogen, and earthy and alkaline phosphates 

 are also present. 



Number of White Corpuscles. The number of white corpuscles per 

 cubic millimeter of blood is much less than the number of red corpuscles, the 

 ratio being in the neighborhood of i white to 700 red. This ratio, however, 

 varies within wide limits in different portions of the body and under normal 



FIG. 1 06. AMCEBOID MOVEMENTS OF A WHITE CORPUSCLE FROM THE FROG. The form 

 changes occurred within ten minutes. The black particles are Chinese ink which had been 

 injected twenty-four hours before into the dorsal lymph sac. (Rauber-Kopsch.) 



variations in physiologic conditions. In the blood of the splenic artery there 

 is but i white to 2260 red, while in the splenic vein there is i white to every 

 60 red; or about thirty-eight times as many as in the artery. In the portal 

 vein there is i white to 740 red, while in the hepatic vein there is i white to 

 170 red. 



The total number of white corpuscles per cubic millimeter has been 

 estimated at from 5000 to 10,000, though the average is about 7500. The 

 number, however, is influenced by a variety of physiologic conditions. The 

 ingestion of food rich in protein material raises the count from 30 to 40 per 

 cent., as compared with the count before the meal. In the new-born the 

 number is greater than in adults 17,000 to 20,000 per cubic millimeter. 

 Cabot states that 30,000 is never a high count after a meal in infants under 

 two years. In the later months of pregnancy, especially in primiparae, the 

 number increases to 16,000 to 18,000. Many pathologic conditions of the 

 body also influence the count very considerably. 



