132 ESSENTIALS OF BACTERIOLOGY. 



drop of blood drawn with a needle, brought on a well-cleaned 

 cover-glass, and immediately covered with a second cover- 

 glass. This is now examined with a strong objective (dry sys- 

 tem) by day-light. 



If, now, a stained preparation is wanted, the cover-glasses are 

 slid apart, passed three times through the flame, and a concen- 

 trated solution of methylin-blue left on for a few minutes. 



Still better is it to allow a drop of methyliu-blue solution in a 

 little ascitic fluid to flow slowly on the cover-glass before the blood 

 has become dry. The finer structure will then be more plainly 

 brought out. Laveran recommends the strong objective of the 

 dry system for examining. 



Pathogenesis. These organisms have been found only in 

 malarial diseases, and they have been constantly found. Malarial 

 paroxysms have been produced in a healthy person by inocu- 

 lation of blood containing such organisms. They disappear 

 under the use of quinine. 



Golgi finds certain types constant in tertian, and others again 

 peculiar to quartan. 



Some, however, hold all these various forms as nothing more 

 than changed blood-corpuscles. The impossibility of obtaining 

 a pure culture leaves the question still in doubt. 



Grassi and Fektti claim to have produced in sparrows and 

 man, by injection of the blood of malarial persons, malarial 

 fever, and found the specific parasites for the different forms. 

 The amoeboid or intra-corpuscular give rise to the typical inter- 

 mittent fevers. In the crescent-shaped extra-corpuscular, pro- 

 ducing the dumb ague or irregular fever, three different amoebae 

 were found. 



Hsemoeba praecox produces the quotidians. 

 " vivax u u tertians, 



malaria? " " quartans. 



They place them with the Rhizopoda. 



