140 Marvels of Pond- Life. 



CHAPTER XIII. 



CONCLUSION. 



HE creatures described in the preceding pages 

 range from very simple to highly complicated 

 forms, and in describing them some attention 

 has been paid to the general principles of classification. 

 The step is a wide one from the little masses of living 

 jelly that constitute Amcebse to the Rotifers, supplied 

 with organs of sensation — eyes, feelers (calcars), and the 

 long cilia in the Floscularians, which seem to convey 

 impression like the whiskers of a cat — together with 

 elaborate machinery for catching, grinding up, and 

 digesting their prey, and which are also well furnished 

 with respiratory and excretory apparatus, ovaries, &c. 

 In the polypi and polyzoa may be observed those 

 resemblances in appearance which induced early natura- 

 lists to group them together, and also the wide dif- 

 ference of organization which marks the higher rank 

 to which the latter have attained. Amongst the ciliated 

 infusoria important gradations and differences will also 

 be noticed, some having only one sort of cilia, others 

 two sorts, and others, again, supplied, in addition to 

 cilia, with hooks and styles. No perfectly satisfactory 



