Fig. ii 



Fig. 12 



Fig. ii — Paramoecium. (From Kellogg's Elementary Zool.) 

 Fig. 12 — Voriicella, one individual with the stalk coiled, the other 

 with the stalk extended. (From Kellogg's Elementary Zool.) 



Fig. 13 — Pathogenic Protozoa; a group of intestinal parasites. 

 A, B, Megasioma entericum, C, Balantidum entozoon. (After Calkins.) 



