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Page:Popular Science Monthly Volume 57.djvu/450

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POPULAR SCIENCE MONTHLY.

hill country and the fertile valleys that send their waters to the river Beni. On the other side lay a high plateau, at a uniform altitude of from twelve thousand to thirteen thousand feet, from which the tops of low rocky hills here and there emerged. This plateau had obviously been at one time submerged; evidence was plentiful that in ancient times the glaciers enveloped a large part of the slopes that led down to it from the main Cordilleras and reached down many miles farther than now. In the immense pile of débris left by the glaciers deep valleys were afterward cut by the action of water, and into these valleys the glaciers of a second period of advance protruded their snouts, depositing moraines that could still be traced in situ as much as four or five miles below the present limit of the ice. Contrary to the apparently general impression that the peaks of the Cordilleras were volcanic, the author had not been able to find any trace of volcanic action along the axis of the range. The Cordillera Real had been elevated by a great earth movement, and the heart of the range consisted of granites, schists and similar rocks. The whole range might be described as highly mineralized. Gold was found at several points, but the chief auriferous valleys were those on the east side of the range. Just below the snowy mass of Cacaaca on the west was a really enormous vein of tin; and antimony, cobalt and platinum have been found in different parts. The great copper deposits were not in this range, but farther west. The flora of the high regions of the Cordillera Real was apparently sparse, but is probably more abundant in the rainy season. Bird life was more prolific and birds were numerous, at suitable places, up to an altitude of seventeen thousand feet above the sea.

 

ZOOLOGY.

The most recent elementary textbook in zoölogy is from the press of The Macmillan Co. Professor and Mrs. Charles B. Davenport are the joint authors. It is recognized now-a-days that what the general high school or elementary student in zoölogy needs is not professional training in that subject, but rather an opportunity to view the field so that he may have as wide an acquaintance as may be of the forms of animals and of their doings. This he needs that he may have an interest in the things of nature and that he may be a more intelligent member of society in the things pertaining to his welfare as affected by animals. The book is therefore an attempt to restore the old natural history in a newer garb. The text is divided into twenty-one chapters. The first of these deals with 'The Grasshopper and its Allies,' followed by others upon the butterfly, beetle, fly, spider, etc., similarly treated. Each chapter has one or two 'keys'—that is, arrangements whereby the families of animals may be determined. The book is richly illustrated by means of half-tone and line reproduction: a number of photographs are from life, and one of these is a flash-light photograph of a slug and an earthworm crawling upon a pavement at night! Outlines for simple laboratory work and a list of books dealing with the classification and habits of American animals are to be found in an appendix. Many good things might be said of this contribution to zoælogical text-books. This ought to be said, that it will be a book which will be of value to any person who, while upon his holiday trip, wishes to learn about the animals he may come across.

 

ORNITHOLOGY.

Mr. Chapman is equally at home with camera or pen. In 'Bird Studies with a Camera, with Introductory Chapters on the Outfit and Methods of the Bird Photographer,' he gives us some of his many experiences from Central Park to the swamps of Florida and the bare rocks of the Gulf of St. Lawrence. The first two chapters are devoted to a brief discussion of the outfit and methods of the bird photog-