Fore Foot. Hind Foot. Fore-arm. Leg. Upper Molar. Lower Molar.
RECENT.
EQUUS.
PLIOCENE.
PLIOHIPPUS.
PROTOHIPPUS
(Hipparion).
MIOCENE.
MIOHIPPUS
(Anchitherium).
MESOHIPPUS.
EOCENE.
OROHIPPUS.

FOOTNOTES:

[5] I use the word “type” because it is highly probable that many of the forms of Anchitherium-like and Hipparion-like animals existed in the Miocene and Pliocene epochs, just as many species of the horse tribe exist now; and it is highly improbable that the particular species of Anchitherium or Hipparion, which happen to have been discovered, should be precisely those which have formed part of the direct line of the horse's pedigree.

[6] Since this lecture was delivered, Professor Marsh has discovered a new genus of equine mammals (Eohippus) from the lowest Eocene deposits of the West, which corresponds very nearly to this description.—American Journal of Science, November, 1876.

FIGHTING PESTS WITH INSECT ALLIES

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Leland O. Howard

[Dr. Howard is Chief of the Division of Entomology in the United States Department of Agriculture at Washington. He is a lecturer at Swarthmore College and at Georgetown University. He has written “The Insect Book,” published by Doubleday, Page & Co., New York; and a work on Mosquitoes, issued by McClure, Phillips & Co., New York. Both are books of interest from the hand of a master: they are fully illustrated. The narrative which follows appeared in Everybody's Magazine, June, 1901.]

Some twenty-five years ago there appeared suddenly upon certain acacia trees at Menlo Park, California, a very destructive scale bug. It rapidly increased and spread from tree to tree, attacking apples, figs, pomegranates, quinces, and roses, and many other trees and plants, but seeming to prefer to all other food the beautiful orange and lemon trees which grow so luxuriantly on the Pacific Coast, and from which a large share of the income of so many fruit-growers is gained. This insect, which came to be known as the white scale or fluted scale or the Icerya (from its scientific name), was an insignificant creature in itself, resembling a small bit of fluted wax a little more than a quarter of an inch long. But when the scales had once taken possession of a tree, they swarmed over it until the bark was hidden; they sucked its sap through their minute beaks until the plant became so feeble that the leaves and young fruit dropped off, a hideous black smut-fungus crept over the young twigs, and the weakened tree gradually died.