212 MICROSCOPY FOR BEGINNERS. 



to one inside wall by the tips of her toes, and as the 

 tube lengthens by the deposit of new material at the 

 top, she takes a step forward so as to keep her expanded 

 ciliary disks in the open water. If the student will al- 

 low a mixture of fine indigo and water to run under the 

 cover-glass, he will see the formation of the sheath. A 

 blue ring of indigo will very soon appear at the top of 

 the soft tube. 



In appearance the Eotifer resembles Rotifer vulgdms 

 (Fig. 148), and when out of the tube, which she can 

 leave at will, has similar actions. There are two ciliary 

 disks, and usually two eye-spots. The foot is long, and 

 can be drawn into the body by telescopic joints. It has 

 three toes, the middle one being the longest. The eggs 

 are hatched within the parent's body. The Rotifers oc- 

 cupying the branches of the sheath are probably all 

 members of the same family mother, children, and 

 grandchildren the young forming the branches. 



There is a species of this genus which does not form 

 a sheath. It may be known by its resemblance to Ro- 

 tifer vulgaris, and by the three toes, the middle one 

 being the longest. 



5. MELICERTA (Fig. 145). 



The sheath of Melicerta resembles that of no other 

 common Rotifer. It is built of pellets, which she makes 

 and places in rows around her body, thus erecting a red- 

 dish or yellowish-brown lorica that cannot be mistaken. 

 The body itself is colorless, and is always attached by 



