COPROZOIC PROTOZOA IN THE FAECES 67 



Cysts. ThiiiK- enveloped cvsts are rounded or oval in 

 form, and measure 7-8^ in diameter. Thev are uninucleate. 



Objects present in the faeces 



An enormous number of different kinds of objects occur 

 in the faecal matter, some of which mav resemble super- 

 ficially intestinal protozoa and thus may be mistaken for 

 them. These objects are derived from foods, microorgan- 

 isms present in drinking or cooking w^ater, or the digestive 

 tract itself. To deal with all of them is bevond the scope 

 of the present manual. The best information will be ob- 

 tained bv frequent examinations of one's own faeces. Here 

 only a few examples will be mentioned. 



Neutral fats. Fats often occur as spherical bodies of vari- 

 ous sizes. Thev are highly refractile and mav resemble 

 superficiallv cvsts of amoebae. However, thev do not have 

 any wall and do not show the differentiation of the con- 

 tents of a cyst. A little care will easily allow one to realize 

 the real nature of fats. They stain with sudan HL In 

 stained smears, the fat droplets are usually dissolved and 

 do not appear. 



Coccidia. Coccidia are common parasites of animals that 

 are important sources of human foods, and consequenth^ are 

 often found in the faeces. The oocysts of Eimeria sardinae 

 Thelohan (Fig. 15, l) parasitic in the testis of sardines, 

 mackerel, herrings, etc., and of E. clupearum Thelohan 

 (Fig. 15, 2), a parasite of the liver of mackerel, herrings, 

 etc., are sometimes passed in human faeces. Both oocvsts 

 are spherical, but the former are 33-55m in diameter and 

 contain four fusiform spores, while the latter measme 

 about 20n in diameter and contain four oval spores. The 



