180 MARVELS OF POND-LIFK. 



ramifications of the stomach answer the purpose 

 of arteries, and convey the nutrient fluid to various 

 parts of the body. It is also likely that they 

 minister to the function of respiration. 



The cilia on the surface, which are arranged in 

 parallel lines, are best observed when the animal 

 is slightly flattened in a live-box; but this process 

 produces a considerable derangement in the relative 

 position of the internal parts, and they can only 

 be well seen when it is immersed in plenty of water, 

 and is polite enough to stand still, and submit 

 his digestive economy to a steady gaze. The only 

 way to succeed in this undertaking is to have a 

 large stock of patience as well as a convenient 

 cell or trough. The table must be kept steady, and 

 the prisoner watched from time to time, and at last 

 he will be found ready for display. 



Pritchard says this animal, whose name is Tra- 

 chelius ovum^ is an inhabitant of stagnant bog 

 water, and has been found encysted. My specimens 

 could not be called plentiful, but for several weeks 

 I could generally find two or three, by filling a 

 four-ounce vial from the glass jar, and examining its 

 contents with a pocket-lens. If none were present, 

 another dip was made, and usually with success. 



One evening I caught a good specimen by means 

 of the dipping-tube, and cautiously let it out, ac- 

 companied by a drop of water, on the glass floor 



