THE MICROSCOPICAL AQUARIUM. 



37 



Such are the Cosmarium, Closterium, Pediastrum, and 

 Scenedesmus, figured below, — all Desmids. 



As these all multiply by simply di- 

 viding into two, — and that frequently, 

 — it will be understood that a colony 

 is soon established if one or two speci- 

 mens are introduced. Figs. 25, 26, 27 

 represent species of Diatoms, in which 

 the plant is enclosed in tiny boxes of 

 pure flint. 



It will be well to obtain a few specimens of the brittle- 

 stemmed Chara or Nitella, interesting on account of the 

 peculiar protoplasmic movements in the cells. Fig. 28 

 shows a portion of Chara about the natural size. 



Fig. 20. 

 Kugleiia. 



Fig. 21. 

 Cosmarium. 



Fig. 22. 

 Closterium. 



Nor will our colony be wanting in representations of 

 minute animal life. Multitudes of the remarkable Wheel 

 Animals or Rotifers will glide through the water, their 



Fig. 23. 

 Pediastruin. 



Fig. 24. 

 Scenedesmus. 



wheel-illusions in active work, drawing the smaller 

 Monads to their mouths, and great will be our joy when 

 we find specimens of that industrious rotifer Melicerta, 



