226 



AQUATIC MICROSCOPY FOR BEGINNERS. 



pulverized indigo and water to run under the cover- 

 glass, he may witness the formation of the sheath. A 

 blue ring of indigo will speedily appear at the top of 

 the soft tube. 



5. Melicerta (Fig. 158). 



The sheath of MelicMa resembles that of no other 

 common Rotifer. It is built of pellets, which she 

 makes and places in rows around her body, thus erect- 

 ing a reddish or yellowish-brown lorica that cannot be 

 mistaken. The body itself is colorless, and is always 

 attached to an aquatic support by the tip of the long 

 foot. The ciliary disk consists of four parts or lobes 

 of different shapes and sizes, and the little 

 creature has in addition to these, a peculiar 

 and rather complicated organ for making 

 the pellets. 



The whole front part of the body can be 

 folded together into a rounded mass when 

 Melicerta is frightened and retires to her 

 sheath. When her fright is over, she 

 slowly protrudes this rounded mass from 

 the aperture, gradually spreads it open, 

 sets the cilia at work, and proceeds to eat 

 and to build. The last she seems to do 

 almost continuously, up to a certain point. 

 Fig. 158.— Mdi- for as her body grows, her house must be 



c^rta ringens. . . 



enlarged to receive it. 

 The ciliary disk nf Melicerta will repay the most 

 careful study. And careful observation will be needed 

 to learn just how the three distinct currents that she 

 makes in the watei are produced. One current 

 brings food-particles to the mouth, where she selects 



