68 Bulletin No. 159 



twenty-one inches. The food as seen under the microscope 

 consists of the sHmy ooze which collects in summer on the 

 bottom and over objects in the water. It contains vast 

 numbers of microscopic plants known as diatoms, of des- 

 mids, and of the rod-shaped Oscillaria, of numerous pro- 

 tozoans, and of granular matter, vegetable and animal, in 

 process of decomposition. 



The adult frog is one of our largest American species, 

 next in size to the bull frog and a good deal like it. The 

 bull frog, however, prefers swamps, and is common in bot- 

 tom lands along the Mississippi River in the West. The 

 spring frog frequents springs and spring-fed streams. It 

 may always be distinguished by the incurved edges of the 

 webs of the hind feet and the presence of a glandular fold 

 along the sides of its body. An example of the adult caught 

 some years ago in Edmonson County near Mammoth Cave 

 had fed on water beetles. 



VEGETATION IN AND ABOUT THE STREAMS. 



A rust-brown material, coating objects in the streams, 

 looked at first like iron and I thought might result from the 

 washings of mines and heaps of slaty material thrown out of 

 them. It proved when examined with the microscope to be 

 a filamentous alga, and was composed of fiber-like strands 

 becoming smaller and smaller as they divided. I judge they 

 are denuded strands of Batrachospermum. They were not 

 in good condition for examination when I reached home. 



Algse were of course common in the waters, on rocks 

 and wood. With diatoms and desmids, both of which were 

 numerous, they constitute the most important feature of the 

 aquatic vegetable life of these waters. 



But one strictly aquatic plant of the higher groups was 

 observed: A slender species of Nitella was collected in 

 August from the Cumberland. 



The banks of all the streams are fringed more or less 

 closely with shrubs and trees. Without giving them any- 



