22 



OUTLINES OF NATURAL HISTORY. 



floating particles of food to the month. At the hinder- 

 end of the body there is a little pair of pincers, composed 



of two little diverging "toes," 

 and by means of these the 

 animal can at wUl moor itself 

 to the stems of aquatic plants. 

 We can also observe that the 

 integument is to a certain ex- 

 tent ringed or transversely 

 wrinkled, though not nearly 

 in such a marked manner 

 as in the true Worms. 



As before remarked, the 

 animal is nearly transparent, 

 and its internal anatomy can 

 thus be readily studied. On 

 one side of the locomotive 

 wheel is placed the opening 

 of the mouth (fig. 9, h), to 

 which a depression in the disc 

 conducts. The upper por- 

 tion of the gullet (c) is much 

 dilated, and contains a com- 

 plicated series of horny jaws. 

 There is a well - developed 

 stomach {d), and the intes- 

 tine opens into a chamber, 

 with which the "w'ater-ves- 

 sels " also communicate. 



Fig. S.— Rotifera. Eosphora aurita, rni " wntpvvp^cipk " iiwt 

 one of the Wheel-animalcules. En- -"-^^ watei-\ esseib, jUbL 

 larged about 250 diameters. (After alluded tO, are two tubes ((/ 



'^^^^^' (/), which run along the sides 



of the body, and open behind into a contractile bladder (/). 

 What the exact function of these vessels may be is un- 

 certain, but they are supposed to be connected with the 

 process of respiration. 



There is no distinct heart, or true blood-system of 

 vessels. The nervous system, however, is well developed, 

 and consists of a little double nervous mass (h) situated 



