50 



Aquatic JLite 



nor some representatives of the Oscilla- 

 toriaceae, whose peculiar wavy motion 

 has not yet been satisfactorily explained. 

 The latter, generally massed into skin- 

 like layers, may be seen even with a 

 magnification as low as 80 to 100 diame- 

 ters, and with the diatoms and desmids 



gether anywhere in nature. One will 

 never look in vain, for instance, for 

 Paramecium and Chilodon, and it is an 

 interesting fact that the largest of all 

 infusorians, Spirostomum ambiguum, 

 which is even visible to the naked eye as 

 a "white worm" of a length of about one 







•* 



1. Actinoptychus heliopelta, a marine diatom. 2. Closterium, a desmid, from the side of an 

 aquarium (Carl L. Hartshorn). 3. Micrasterias, a desmid. 4. Spirogyra, a filamentous algae, 

 in conjugation (Charles M. Breder, Jr.). 5. Pediastrum pertusum. 6. Triceratium favus, 

 a marine diatom. 7. A portion of the radula or tongue of a snail. 8. A scale of the mouth- 

 breeder, Haplochromis strigigena (Charles M. Breder, Jr.). 9. Bacteria, Bacillus subtilis, 

 from an aquarium. 10. Filamentous desmids and diatoms. 11. Diatoms, Isthmia sp., on Mi- 

 crocladia Coulteri, a seaweed. Photomicrographs by Charles P. Titus except as otherwise 

 noted. 



they form, as "crawling plants," some millimeter, is most easily obtainable from 



of the most interesting forms of micro- 

 scopic life. 



One will never fail to find in an 

 aquarium many of the lively infusorians; 

 many an old aquarium will furnish a 

 larger variety than may be found to- 



almost any permanent aquarium. Then 

 there are almost always present during 

 the summer months, appearing like a 

 white fungous growth on plants, the 

 charming Vorticella, showing under the 

 microscope one of the wonders of life — 



