Abstract:
In the previous article (this journal) details were given of the source and method of isolation of five strains of rickettsia. These strains have been maintained either by serial passage in guinea pigs, or by cultivation on the chorio-allantoic membrane of the chick embryo, or by both methods. In this paper the microscopic appearance of the scrotal exudate and method of egg-membrane cultivation will be described and the morphology of the rickettsias compared particularly in view of Pinkerton's classification of this group of organisms.