illustrations there are figured here a cell of the yeast fungus (Fig. 72) 
and some ripe spores of the corn-smut (Fig. 73). 
Unicellular plants, belonging to the large group of algae, are 
frequently found in feces owing to their occurrence in water supplies 
of domestic animals. Some of these are figured here. Two of the 
diatoms figured (Figs. 74 and 75) have somewhat the outline of whip¬ 
worm eggs, but have a quite different internal organization and have 
Fig. 79. One of the Schizophyceae, or blue-green algae, Chroococcus turgidus, show¬ 
ing 4 cells surrounded by a gelatinous envelope, x 500. From Campbell, 1902. 
the distinct and delicate striation which is characteristic of the diatoms; 
the other diatom (Fig. 76) has a slight resemblance to the well known 
figures of the bothriocephalid tapeworm egg, but this diatom is flat, 
whereas the tapeworm egg is almost spherical. Various cells of algae 
are figured as figures No. 77, 78, and 79 to show the superficial re¬ 
semblance of these cells to parasite eggs. The presence of chlorophyll 
in most of the algae is sufficient to distinguish them from parasite eggs. 
Among the confusing objects which may be mistaken for worm 
eggs are the eggs of parasitic or free-living mites. They are especially 
likely to occur in the feces of mangy animals. These eggs (Fig. 16) 
are usually larger than most worm eggs. 
66 
