According to the plan of nature animals are compelled either directly or indirectly to lay under tribute the plant world in order to obtain food; and so completely have they done so that it is doubtful if any, among the many thousands of species of the latter, are exempt from attack. Being thus exposed to the wholesale appetites of higher creation plants have been forced into the evolution of devices for warding off animal attacks.
Proceedings of the Iowa Academy of Science
©1917 Iowa Academy of Science, Inc.
Ewing, H. E.
"Mites Affecting the Poison Oak,"
Proceedings of the Iowa Academy of Science, 24(1), 323-326.
Available at: https://scholarworks.uni.edu/pias/vol24/iss1/51