INFUSORIAL ANIMALCULES. 47 



serted in the arched portion of the jaws. These organs are frequently seen in 

 action, when the creature is feeding, and are distinguished without difficulty. 

 Between the rotatory organs are situated the eyes of the animalcule, which are 

 two in number, and of a red hue. For certain reasons, Dr. Ehrenberg has been 

 led to suppose that these eyes are not simple, but complex, like those of insects ; 

 each organ of vision consisting of a number of lenses, which form as many sep- 

 arate images of a single object before them. There is also a tube projecting from 

 the neck, the position of which is indicated at 6, in figure 61 ; through this, 

 water flows into the body of the creature, for the purpose of affording constant 

 supplies of air. The wheel-animalcule moves through the water by two differ- 

 ent methods. The first is by swimming, which is accomplished by the rotatory 

 action of its crowns of cilia ; and in the second method the tail is employed. 

 This member is provided with two pairs of projections, g g, figure 59, which may 

 be termed feet, and is likewise divided at the end. By alternately attaching its 

 head and tail to the surface ot' the object upon which it moves, the animalcule 

 advances in its course, bending itself upward in the manner of a caterpillar, in 

 order to effect this object. Wheel-animals progressing in this way are delineated 

 in figures 62 and 63. In the various figures presented, we perceive joints and 

 rings, like those which surround the common worm. The joints are not limited 

 in number, nor confined to any particular situation on the body of the animal- 

 cule, and where any joint occurs the smaller parts slide in and out of the larger, 

 like the tubes of a telescope. From this peculiarity these Infusoria can assume 

 the form of a sphere, the head and tail being drawn within the body. This 

 movement is nearly effected in figure 64, the toes being still attached to a stem. 

 In figure 65 the animalcule is entirely contracted, and forms a spherical ball. A 

 number of the eggs of the wheel-animalcule are shown below figure 59. 

 In form they are oval, with a richly granulated surface. They vary 

 in color, being sometimes of a delicate pink, and at others of a deep golden 

 yellow. 



THE CROWN WHEEL-ANIMALCULE, OR STEPHANOCEROS. This elegant little 

 creature has received the name of Stephanoceros, from the Greek word Stephanos, 

 a crown. It is found in ponds, amid the leaves of aquatic plants, and usually 

 measures one thirty-sixth of an inch in length. A specimen of these Infusoria, 

 which was carefully studied and delineated by Dr. Mantell, is represented in 

 figure 66, and displays at a glance its singular peculiarities of structure. 

 The Stephanoceros is here beheld fully extended, enclosed in a transparent, 

 cylindrical case, a a, which is flexible in its nature, and is attached to the 

 body of the animalcule, near the head, as seen at c. The head is adorned with 

 a crown, consisting of five long branching arms, d d d d d, each of which is 

 fringed with fifteen small circles of cilia, that are perpetually vibrating. Upon 

 the currents produced by the motion of the cilia, the prey of the Stephanoceros 

 floats, till it comes within its grasp, when it is seized by the long arms of the 

 creature, and firmly held until it is devoured. In the figure several animalcules 



