50O MICRO-ORGANISMS AND DISEASE [chap. 



measuring not more than a fifth to a seventh of the diameter 

 of a red blood-corpuscle ; in this host the parasite performs 

 active amoeboid movement, hereby changing continually its 

 shape ; but it gradually increases in size and consumes the 

 substance of the red blood-corpuscle, leaving black pigment 

 granules — iron-free melanin — in the disc. These pigment 

 granules, as the parasite grows to the size of the original red 

 blood disc, are now contained within the body of the 

 parasite, in which they appear uniformly distributed. When 

 the disc of the red blood-corpuscle is entirely consumed by 

 the growth of the parasite this latter appears free in the 

 blood plasma, its substance filled with the melanin granules ; 

 some of these free parasites have ciHa by which they move 

 actively — these are the corpuscles seen by Laveran. Next, 

 the pigment granules aggregate in the central part of the 

 parasite and the peripheral, pale, homogeneous portion 

 gradually undergoes a more or less regular mode of seg- 

 mentation, in the course of which small globular particles 

 or sporules become constricted off from the main body ; 

 when this segmentation has been completed the young 

 gemms or sporules all disappear from the blood, so also the 

 pigmented central parts, and are stored up in the spleen, 

 liver, and bone marrow ; this terminates one febrile attack. 

 The next febrile attack is caused by the sporules again in- 

 vading the blood-corpuscles of the general circulation, and 

 herein undergoing the same series of changes as just 

 described. So that each febrile stage comprises the in- 

 vasion of the blood- corpuscles by the sporules, the germina- 

 tion, amcEboid movement and growth of these latter within 

 and at the expense of the former, then the gemmation and 

 segmentation into a new crop of sporules, and finally the dis- 

 appearance of these from the general circulation. Golgi ^ 

 1 Fortschritte d. Medizin, 1S89, No. 3. 



