MICROSCOPE IN AQUARIUM WORK 



129 



in the water. Also with high magnification the field of vision and the 

 area of sharp focus are smaller, while movements are apparently much 

 more rapid, making observation difficult. 



The majority of the valuable organisms are rotifers. These move 

 in a steady, revolving or rotating manner. On page 206 will be found 

 instructions for propagating these organisms for purposes of feeding young 

 fish. Most rotifers can be readily identified as such because they swim 

 through the water by means of circlets of hairs or cilia arising from the 

 front of their heads, by the vibratile action of which they swim and 



Fig. 109. Common Forms of Microscopic Animal Lite in Fresh Water 



(Greatly magnified) 



1. Loxodes, a very common form 



2. Ceratium, a very common form, especially in ponds and lakes 



3. Paramaecium, a very common form, the slipper animalcule 



4. Bursaria, a very common form, one of the largest 



5. Stylonycha, a very common form, found everywhere 



6. Phacus, not so common as the above numbers 



7. Spirostomum, common everywhere 



8. Euglena, common everywhere 



9. Chilodon, common everywhere 



10. Trachelocerca, common everywhere, the swan animalcule 



11. Eupolotes, not an aquarium in America without examples 



12. Dadinium, predaceous, feeds on paramaecium and others 



13. Trachelocerca, small but plentiful 



14. Coleps, the barrel animalcule, common 



