RECREATIONS WITH THE MICROSCOPE 



377 



vorous animals may utilize. In this 

 manner food material is being prepared 

 that the larger animals, fish, turtles, 

 amphibians, etc., may feed upon. 



In no way can this fact of the pond 

 being a minature world be better dem- 

 onstrated than by collecting a handful 

 of filamentous algae, of the genera 



the algae or run clumsily about on the 

 bottom. 



As we look closer into the basin hold- 

 ing our handful of algae we may observe 

 many small dots or specks rapidly mov- 

 ing through the water. Under the mi- 

 croscope these are seen to be minute 

 crustaceans known as water fleas (Cla- 



I MM. 



THE SIDA WATER FLEA. 



Cladophora, CEdogonium, or Spirogyra, 

 and placing it in a basin of water. It 

 is soon seen to be filled with an abun- 

 dance of animal life consisting of 

 snails, leeches, crustaceans, worms, in- 

 sects, and other forms. 



The first objects to attract our at- 

 tention are the scuds or Amphipods 

 which dart about in an effort to find 

 concealment. These little crustaceans 

 are usually represented by Gammarus 

 and Hyalclla, the latter being the most 

 abundant of these crustaceans. Related 

 to the scuds, and almost as abundant, 



docera). These creatures may be known 

 by the large compound eye and by the 

 peculiar branched swimming organ, the 

 antennas. The antennae vary much in 

 form and size and are largely used in 

 classifying the different species. The 

 shell which encases these tiny creatures 

 is usually so transparent that the internal 

 organs of the body may be plainly seen 

 and studied. Thus the digestive and re- 

 productive systems may be seen to occupy 

 the greater portion of the internal cavity 

 and the eggs may frequently be seen in 

 the upper part of the body which is modi- 



I MM. i_ 



-i 



THE LATONA WATER FLEA. 



are the sowbugs or Isopods, of which 

 Asellus communis is the most common 

 species. These animals resemble and 

 are related to the pillbugs or sowbugs 

 that are often so abundant under 

 boards in damp places. Unlike the 

 scuds, the sowbugs crawl slowly over 



fied to form a brood chamber. A com- 

 mon species of water flea, about 3 mm. 

 in length is known as Sida crystallina. 

 Another, smaller, is Latoua setifera. In 

 these animals the antennae are much 

 branched and are extended directly 

 ahead of the animal. In Daphnia the 



