The Ohio ^h[^aturalist, 



PUBLISHED BY 



The Biological Club of the Ohio State Uni'versity, 

 Volume XIV. MARCH, 1914. No. 5. 



TABLE OF CONTENTS. 



Deake— The Food of Rana Pipieiis Schreber 257 



Sterki— Ohio MoUusca, Additions and Corrections 270 



Field Manual of Trees 'J72 



Sewell— Soil Bacteria 273 



Plant Life and Plant Uses 278 



McAvoY— Meeting of the Biological Club 279 



THE FOOD OF RANA PIPIENS SHREBER. 



Carl J. Drake. 



The frogs, Rana pipiens Shreber, dissected for this paper were 

 collected on the peninsula of Cedar Point, Ohio, at various times 

 during the day and evening, between August eighth and August 

 twenty-second inclusive. My notes are entirely derived from 

 the two hundred and nine specimens collected here in the low, 

 wet depressions between the sand dunes, in the weeds and grasses 

 southeast of the Lake Laboratory, and one evening under the 

 electric lights at the Summer Resort. 



The object of this paper is to determine the food of our common 

 leopard frog, Rana pipiens Shreber, and its relation to nature in 

 the neighborhood of its habitat. Owing to the fact that the 

 frog's skin must always be kept moist in order that cutaneous 

 respiration may take place, its habitat is always in close proximity 

 to water, or among wet weeds and grasses. Water also affords 

 the means of escaping from its enemies; one who walks along the 

 margin of a pond or stream will notice that a frog when startled 

 almost invariably makes a jump for the water. In this way the 

 creature has a ready mode of escaping, not only from man, but 

 from anv other creature which might easily overtake it in an open 

 field. 



The frog's food consists of almost any kind of an animal small 

 enough to be seized and swallowed. It has an instinct to snap at 

 all moving objects that come sufficiently near, and will not take 

 dead or motionless animals. Only living and moving creatures 

 are devoured. The frog's tongue is the only organ used for seizing 

 food. It is soft, extensile, attached in front, but free behind, 



257 



