a 4 m 
1 The Ohio Ih^aturalist, 
PUBLISHED BY 
The Biological Club of the Ohio State University. 
Volume XIV. MARCH, 1914. No. 5. 
TABLE OF CONTENTS. 
Drake— The Food of Rann Pipiens Schreber. 257 
Sterki— Ohio Mollusea, Additions and Corrections. 270 
Field Manual of Trees. .. . .272 
Sewell— Soil Bacteria. .273 
Plant Life and Plant Uses . . 278 
McAvoy—M eeting 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 any 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, 
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