374 CLINICAL BACTERIOLOGY. 



is usually collected at the center, frequently in the form of a 

 figure of eight, although it may be distributed throughout the 

 entire crescent ; in the latter event granules are frequently in 

 tremulous movement. The concentrated pigment is invariably 

 still. The crescentic bodies possess a membrane (Mannaberg), 

 which, however, is not visible in all specimens. At times their 

 poles are united on the concave aspect by a delicate curved line 

 (remainder of the host-cell). The crescents are not endowed 

 with ameboid movement ; they have, however, the faculty of 

 slowly changing their form and becoming spindle-shaped, oval, 

 and finally quite round bodies. This transformation, which can 

 be observed under the microscope, takes place quite gradually, 

 in the course often of several hours. In fresh blood-prepara- 

 tions containing numerous malarial parasites, there are always 

 present a few spindles, ovals, and spheres, and Mannaberg is of 

 the opinion that these changes in the shape of the crescents are 

 dependent exclusively, or almost exclusively, upon the removal 

 of the parasite from the human body, and that they do not 

 occur at all, or but exceptionally, within the blood-vessels. By no 

 means all crescents, further, undergo the changes in shape de- 

 scribed, but the larger number retain their shape in blood-prepara- 

 tions preserved in a moist chamber. In the sphere resulting from 

 the crescent the pigment is generally arranged in the shape of a 

 wreath. After some time it begins to move, and, with tremu- 

 lous movement, to intermingle, and soon the moving granules 

 of melanin occupy the entire cell-body. Flagella also then form, 

 and the entire body suddenly engages in jerking movements, 

 while at the periphery projections and retractions take place. 

 After some time processes resembling in form the finger of a glove 

 appear, which are formed by the membrane of the body. This 

 membrane ruptures, the processes retract, and long, slender fila- 

 ments are thrust out from them, which actively lash themselves 

 about. These flagella usually present a bulbous enlargement at 

 their free extremity, and they often exhibit in their course knob- 

 like swellings that appear to change place. From one to five 

 filaments develop from a single sphere. Their active movement 

 soon diminishes, and has entirely disappeared after from fifteen 

 to thirty minutes. The resting filaments remain attached to the 

 body ; although often they separate and then move actively 

 about free in the blood. The membrane ruptured in the exit 

 of the flagella becomes rolled together and occupies the per- 

 iphery of the sphere in the form of a globule or a ringlet. Such 

 globules distinguish the spheres resulting from the crescents from 

 the other spherical elements of the malarial parasites already 

 described. Further, the spherical bodies resulting from the 

 crescents have, also after the loss of their membrane, when, 

 therefore the double contour is no longer present, still a much 



