114 ELEMENTS OF APPLIED MICSOSCOPY. 



crease of white cells, accompanies all acute inflamma- 

 tions as well as certain other conditions and may affect 

 any one type of cells or all of them. In inflammations 

 it is the polymorphonuclear neutrophiles which are 

 increased; in trichinosis, on the other hand, the eosino- 

 philes may reach 50% of the total. 



5. The Detection of the Malarial Parasite. — Blood ex- 

 aminations are also undertaken for the diagnosis of 

 malaria. The Protozoon malarial parasites gain entrance 

 to the body from the bite of an infected mosquito in the 

 form of minute spore-like bodies which penetrate the 

 red corpuscles and there assume a crescentic form. Later 

 the organism becomes amoeboid, sends out blunt pseudo- 

 podia, and develops nuclear granules. As it matures, it 

 occupies the greater part of the red corpuscle and finally 

 begins to divide, appearing in a rosette form, at last sepa- 

 rating and discharging into the blood stream granules 

 like those with which the cycle began. 



Blood may be examined in its fresh condition for the 

 malarial parasite, but better preparations are obtained 

 by staining. The Wright-Leishman method yields ad- 

 mirable results, the cytoplasm of the parasite being 

 stained blue and the nuclear granules a color varying from 

 lilac through red to almost black. The general appear- 

 ance of blood-cells containing the parasite of tertian 

 malaria, HcBmamceba vivax, is indicated in the two upper 

 fields of Fig. 45 ; the lower field shows a later flagellated 

 stage in the flood stream. Only considerable experience 

 in the examination of normal blood will enable the ob- 

 server to recognize the invading organism with certainty. 



