ZOOLOGY. 



Thus the 40,000 females from such a meal would soon supply 40,000,000 

 young worms for the infection of the muscles, with the ability of renew- 

 ing the supply at short periods. Perfect cooking is the only sure safe- 

 guard against the possibility of infection. 



FIG. 93. 



FIG. 93. Diagram of a sagittal section of a Rotifer, b, brain; bl., excretory 

 bladder; c, cloaca, the common opening of digestive and reproductive organs; co, 

 coelom; e, eyespot; ex, excretory canal; /, flame cells; f.g., foot gland; ft., foot; g, gut; 

 m, mouth; m.f., longitudinal muscle fibres; mx, mastax; o, ovary; ph., pharynx; s.g., 

 salivary gland; t, tentacle; tr, trochus, or cilia-bearing disc. 



Questions on the figure. What sets of organs and functions are in- 

 dicated in the diagram? Does this seem a lower or higher form than the 

 other types studied in this chapter? What are your grounds for your 

 answer? What indications of segmentation are represented in the figure? 

 Is the mastax in the stomodaeum or mesenteron? Where do the various 

 authors classify Rotifers ? 



