C. sandoni is found chiefly in the gut, but the gastric caeca may become involved. Resistant bodies are formed in the rectum by unequal division of flagellates adherent to the rectal epithelium. This gives rise to non-flagellate forms which remain attached to the flagellum or the"parent" cell. These forms later become smaller and ovoid and, finally, invested in a protective pellicle. They become detached and are found in the feces. An exptl. infection of another hemipteran, Cenaeus carnifex, is descr. and C. sandoni is compared with C. familiaris.