FIG. I. THE PARASITE OF TERTIAN FEVER, H.'EMAMCEBA V1VAX 

 (ROSS). HIGHLY MAGNIFIED. 



Nos. i, 2, 3, 4, show the growth and the changing shape of the parasite 

 within the blood-corpuscle; Nos. 3, 4, etc., show the aggregation of 

 the pigment, melanin, in the parasite ; No. 5 is a sporocyte, which 

 in Nos. 6, 7, and 8, shows the several stages of sporulation ; No. 9 

 shows the spores derived from a single sporocyte, escaped from the 

 blood-corpuscle and free in the blood-plasm, ready to infect new 

 corpuscles ; No. 10 is a male gametocyte, removed from the body 

 of man, and either in the stomach of Anopheles or on a microscope- 

 slide, forming there flagella or spermatozoa, a, Parasite ; b, red 

 blood-corpuscle ; c, spore ; d, granules of pigment, melanin; e, flagellum 

 or spermatozoon. (From Thayer.) 



FIG. 2. VARIOUS STAGES WHICH THE PARASITE OF THE ^ESTIVO- 

 AUTUMNAL FEVER, H^MOMENAS PR^COX (ROSS), PASSES 

 THROUGH IN THE BODY OF THE MOSQUITO ANOPHELES. 

 MAGNIFIED 2,OOO TIMES. AFTER ROSS AND FIELDING-OULD. 



No. i, Flagella or spermatozoa from male gametocyte (see Fig. i above) ; 

 No. 2, flagelium or spermatozoon entering and fertilizing the female 

 gametocyte; No. 3. the fertilized cell or zygote ; Nos. i, 2, 3, are 

 found in the blood in the stomach of the Anopheles; No. 4, the 

 fertilized cell piercing the wall of the stomach of the mosquito to 

 come to rest at No 5, between the epithelial lining of the stomach 

 and the muscular sheath. 



To face page \ 36. 



