The Leopard frog (Rana halecina, Kahn) and allied species occur in considerable numbers and have a wide geographical distribution. Being entirely defenseless, beset by enemies at every turn-fish, reptiles, birds and mammals-as well as being cannibals among themselves, subject to many diseases and the hardships of great extremes of temperature, they are, withal, able to maintain their numbers.
Proceedings of the Iowa Academy of Sciences
©1892 Iowa Academy of Science, Inc.
"Some Reasons Why Frogs Are Able to Survive,"
Proceedings of the Iowa Academy of Science, 1(Pt. 3), 32-35.
Available at: https://scholarworks.uni.edu/pias/vol1/iss3/15