136 



The Microscope. 



somewhat resembling the shell of a crab. No. 22 

 represents salpina, one of the species. I have occa- 

 sionally found the empty shells of some 

 of these rotifers, and contrived to mount 

 one of them in Canada balsam. 



The fourth tribe which M. Dujardin 

 has included among the rotifers consists 

 of the Tardigrada, or slowsteppers, 

 popularly called "water-bears." They 

 are very fully described in " Marvels of 

 Pond-Life " but a sight of the original 

 is required to give a full idea of the 

 creature's comical aspect. I first ob- 

 served it when examining a quantity 

 of weed in a live-box. The head 

 and a, pair of feet were suddenly poked into view, 

 and I thought, " here is a small larva/ 3 and 



No. 22. 

 Salpina. 



No. 23. Water-Bear. 



expected a long body in several joints to follow, 

 when all at once the creature showed in its complete- 

 ness, walking along a stalk, and more like a young 



