REVOLVING ANIMALS. 13 



white speck I speak of. A dot of the pen thus * will 

 represent its natural size ; and yet this dot is com- 

 posed of about forty organised and complex animals, 

 each one having a distinct individuality. The 

 individuals of which this globe is composed are, 

 as I have already remarked, of a somewhat complex 

 organisation. There is the head with its crown 

 of cilia, which by its vibrating motion resembles a 

 wheel rotating on a pivot. This motion is common 

 to most of this class of animals, and originated 

 the name under which they are classified namely, 

 Botatoria or, commonly, wheel-bearing animalcules. 

 The rotatory motion is, of course, an optical illusion. 

 It is like that of a field of corn set in motion by the 

 wind; and if you imagine the wave -like motion 

 thus produced to move in a circle, you will have 

 before your mental vision the same appearance on 

 a large scale as is produced by the Rotifers. By 

 this motion a little vortex is created in the water 

 around their heads and mouths, and down this tiny 

 whirlpool their food is carried. They have each 

 two eyes ; manducatory, alimentary, and reproduc- 

 tive functions ; also a suctorial foot by which they 

 attach themselves to a common centre. This attach- 



