334 MANUAL OF BACTERIOLOGY. 



ring. The crescents and ovoid bodies are highly refractive 

 and are in length about equal to the diameter of a red cor- 

 puscle, sometimes larger. The round forms are smaller than 

 a red corpuscle, with the pigment arranged centrally in a 

 ring. They may become flagellated after the blood has 

 remained outside the body for some minutes. Any of the 

 extra-cellular bodies may show remnants of the red cor- 

 puscle attached to its side, like a bib. The extra-cellular 

 forms are concerned in the cycle of development of the 

 organism in the mosquito, and are sterile in the human 

 body. They are exceedingly resistant to quinine and may 

 continue in the blood for long periods of time. 



Melaniferous leucocytes (phagocytes) are seen in the 

 blood, being especially abundant after the paroxysm in all 

 forms of malarial infection. 1 



Small-pox and Vaccinia. Micrococci of various sorts 

 have been found in the pustules of small-pox and vaccinia, 

 but indicate only a secondary infection. Other microorgan- 

 isms have been described. The most important are certain 

 bodies often considered protozoa. In both small-pox and 

 vaccinia small round homogeneous bodies, 2 to 4 /* in 

 diameter, have been found in the epithelial cells of the 

 vesicles. Inoculation of vaccine lymph into the rabbit's 

 cornea leads to the production of similar bodies in the 

 epithelial cells of the cornea. W. Reed 2 found small amoe- 

 boid bodies in the blood in cases of small-pox and vaccinia. 

 Vaccine virus that has been filtered through the Chamber- 

 land or Berkenfeld filter is no longer active. From this it 

 may be presumed that the organism causing it is not too 

 small to be seen with the microscope. 



Councilman, Magratli and Brickerhoff, 3 as a result of 



'See also E\vin.u\ Journal Experimental Medicine, Yols. V. and VI. 



'Journal Experimental Medicine, Vol. 11.. 515; sec also, Anna Wil- 

 liams and Flournoy, and W. H. Park, N. Y. Univ. Bull Medical 

 Sciences, Tl., October, 1902. 



3 Journal Medical Research. Vol. IX., May, 1903. 



