504 PROTOZOA 



In a suitably stained preparation (using a chromatin dye) the young 

 parasite appears to be a disk consisting of a basic (blue) periphery, the 

 body, including a metachromatically stained, rounded, compact (red) 

 chromatin body, often called the nucleus, which tends to give the para- 

 site the form of a signet ring, and of a central, pale, unstained area, known 

 as the achromatic zone. 



Later stages up to a certain number of hours show simply changes in 

 size and outline of the blue-stained body. Then the red chromatin body 

 loosens up and presently its substance divides into an increasing number 

 of angular pieces, which are the first evidence of regeneration. By the 

 time that chromatin division is completed the angular chromatin masses 

 will have assumed a rounded form, and will be seen to exhibit ultimately 

 the same strong affinity for certain dyes which is seen in the compact 

 chromatin body of the young ring-like form. At this stage the here- 

 tofore scattered pigment appears in one clump. Good technique will 

 always show a corpuscular remnant even at this time. The achromatic 

 zone mentioned will be seen to develop with the chromatin, and when 

 the next step, namely, the division of the body of the parasite, is seen 

 to be completed, there will be as many achromatic bodies as there are 

 chromatin bodies, each having an equal share of the basic mother-body, 

 each representing a young parasite. These young parasites next escape 

 from their envelope or whatever substance may have held them together, 

 are set free in the plasma, and attack without delay the corpuscles. 



It is an open question as to whether the parasite sits on or lives in 

 the corpuscles. The latter supposition appears to be more plausible, 

 especially because the segmenting form retains to the last a corpuscular 

 remnant and because the young amoeboid form may be seen to dip into 

 the corpuscle, leaving one focal plane and appearing in a deeper one. 

 How could that be possible if it simply adhered to the surface? The 



DESCRIPTION OF PLATE II. 



(The numbers are placed immediately above the respective form.) 

 1 to 4. Young forms ; unpigmented. 



5 to 8. Gradual pigmentation and growth of the parasite ; the chromatin is loosening up. 

 9 to 13. Active division of chromatin from two into twelve or more pieces, which are at first 

 angular, but become rounded. 



14 to 15. Complete segmentation ; collection of pigment in single lump. 



16. Bursting of segmenting parasite and liberation of young forms, each of which de novo infects 

 and destroys a new corpuscle. 

 17 to 19. Young male sexual forms. 



20. Male sexual forms (microgametocyte). The coiled-up, centrally situated chromatin fibrils are 

 the flagella or microgametes. 



21 to 22. Female sexual form ; stain deeper than in male ; less chromatin, situated peripherally ; 

 often extracorpuscular ; macrogamete. (These gametes are the analogues of the crescentic bodies 

 of sestivo-autumnal malaria.) 



23. Abnormally situated accessory chromatin body. 



24. Two parasites maturing side by side. 



25 to 26. Effect of quinine on body of parasite. 



27. Resistant form capable of causing relapse (?). 



28. Abnormal segmentation of immature parasite. 



The various oval and rounded bodies are blood platelets. The red blood corpuscles are simply out- 

 lined ; their color and degree of degeneration when infected will depend entirely upon the technique. 

 The body of the parasite is blue; the chromatin body is carmine ; the pigment is simply shown in 

 black. 



