CHANGES IN THE BLOOD. 311 



Red blood-corpuscles have an especial affinity for eosin and 

 other acid stains, and in a mixture of dyes, such as haema- 

 toxylin and eosin, stain only with one of them, the eosin, 

 which property is termed monochromatophilia. Pathologi- 

 cally, however, they may develop an affinity also for basic 

 dyes ; when stained with haematoxylin and eosin mixture they 

 present a violet or purple color, instead of the normal pink 

 this is termed polychromatophilia. 



Alterations in the leukocytes : Hypoleukocytosis or letiko- 

 penia a deficiency in the number of leukocytes is associated 

 with certain conditions, as, long-continued fevers, like typhoid, 

 when uncomplicated by inflammatory processes ; with tuber- 

 culosis and inanition. 



Leukocytosis a transient increase in the number of leuko- 

 cytes above the normal ten thousand per cubic millimetre is 

 noted in connection especially with inflammatory processes 

 and infectious diseases. The degree of the leukocytosis in 

 pneumonia and most inflammatory affections is regarded as 

 an index of nature's power to combat the disease, its entire 

 absence being an ill-omen. In typhoid fever, malaria, in- 

 fluenza, and acute miliary tuberculosis the leukocytes are not 

 increased, which fact may at times be of some diagnostic 

 value. Usually it is the poly nuclear variety of leukocyte 

 which is increased. Malignant tumors, especially sarcomata, 

 are accompanied by an increase in the number of leukocytes 

 even to the extent of fifty thousand per cubic millimetre or 

 more the small mononuclear being the variety mainly affected. 

 In syphilis, rickets, and other cachexias there may be a similar 

 leukocytosis. There is also an increase in the number of 

 leukocytes after hemorrhage. 



In leukaemia there is an enormous and permanent increase 

 in the number of leukocytes one to three hundred thousand 

 per cubic millimetre in moderate cases. 



Alterations in the blood-plates are as yet but little under- 

 stood. 



The amount of haemoglobin contained in each red globule 

 varies normally with the size of the corpuscle, though patho- 

 logically this relation does not exist. In most cases the 

 amount of haemoglobin in each globule is diminished ; in some 

 cases, however, there is an actual increase in the amount of 



