:U MARVELS OF POND-LIFE. 



of cilia, which look like revolving wheels, and a 

 little below them is seen a gizzard in a state of 

 active work. After a little while she swims away 

 with her wheels going, and her tail, forked at the 

 end, is found to be telescopic, or capable of being 

 pulled in and out. As the cilia play, the neigh- 

 bouring water is agitated, and multitudes of small 

 objects are brought by the whirlpool within her 

 ravenous maw. But the strangest thing of all 

 is that inside her body is seen a young one; in 

 this case a large and fine infant, which, like "a 

 chip of the old block," imitates the parental mo- 

 tions, thrusts forth its cilia, and works its gizzard.* 

 In other genera the eggs are hatched externally, 

 but this one is ovoviviparous, and carries its nursery 

 inside. 



A very slight investigation is sufficient to shew 

 that in the wheel-bearer we have made a great 

 advance towards a higher organization than we 

 discovered in the preceding creatures. We witness 

 what the learned call a "differentiation" of parts 

 and tissues, and a "specialization" of organs. The 

 head is plainly distinguishable from the body, the 

 skin or integument is distinctly different from the 

 internal tissues, behind the eyes we can detect a 



* This was met with in the summer, but is described here to 

 avoid repetition. I do not know whether the eggs are hatched 

 in very cold weather. 



