630 APPENDIX. 



in so doing usually form distinct rays. Then, as in 

 the tertian form, the organism begins to segment ; a 

 marginal indentation is first seen, with lines of radia- 

 tion, and a beautiful rosette is formed, which segments 

 into from six to ten, occasionally twelve, small, spher- 

 ical or ovoid bodies. The character of the pigment, 

 the smaller size of the organism, and the development 

 are differences which separate the quartan from the 

 tertian variety. 



In the quartan malarial fever the blood may show 

 two or more groups of parasites. There may be two 

 groups which reach maturity on successive days, with 

 one day interval double quartan fever; or there may 

 be three groups of organisms maturing on successive 

 days, causing daily paroxysms triple quartan fever. 



II. The -ffistivo-autumnal Parasite (see Plate II.). 

 In the more irregular and as a rule pernicious types 

 of malarial infection which are met with in the autumn 

 months a third variety of organism may be recognized, 

 which has been specially studied by the Italian obser- 

 vers. The youngest forms of this parasite are small 

 hyaline bodies about one-sixth the diameter of the red 

 cell. At first they are quiescent, but later develop 

 active amoeboid movement. They are at this stage 

 not unlike those of the tertian varieties; but the hya- 

 line body is more signet ring-like, more highly refrac- 

 tile, and the central part often looks shaded, as if a 

 more solid body were enclosed within a vacuole. As 

 this form increases the amoeboid movements are well 

 seen. The pigment is in small amount, at first in the 

 form of one or two very dark granules at the margin 

 of the amoebae, and the pigment never becomes so 

 abundant as in the tertian or quartan forms. The 



