A first book in organic evolution

This little book has been written chiefly for the use of students in the Medical Department of the Columbian University. It is designed to serve only as an _introduction_ to the...

In many cells the protoplasm has formed on its periphery a layer of metaplasm which is frequently called a cell-wall. This cell-wall prevents amœboid movements of the protoplasm...

When gromia oviformis reproduces by mitosis it gives off a bud (small cell), which finally separates from the parent form and constitutes a distinct individual. This process may...

Questions of heredity and variation are cytological ones—that is, questions of the anatomy, physiology, physiological chemistry, and pathology of cells. The most important part...

There are two great classes of environmental factors that bring about variations in the germ-cells. One of these classes acts directly on the germ-cells, and is therefore called...

—> Skeletal-cells (e) (a) Germ-cell —> Glandular-cells (e) —> Muscle-cells (e) —> Nerve-cells (e) | | | | | | | | II | | | | | | | | —> Skeletal-cells (f) v v v v —> Glandular-c...

During the earlier ages (=Silurian= and =Devonian=) of this Palæozoic era, the place of the Appalachian chain of mountains was marginal sea bottom; but during the later ages (=C...

These plants of the coal period were remarkable, generalized types, connecting classes now widely separated. During this period the insects increase in variety and numbers along...

In briefly outlining the transmutations of living forms that took place during the Geologic Ages, we have said that changing conditions of life—through an ever-shifting environm...

Eggs that are not protectively colored are usually white or of some uniform pale color, and are concealed by the birds in covered nests or in holes in trees or in the ground. Ma...

=Mimicry.= Protective resemblance of a harmless animal to another of a different species that is harmful is known as mimicry. Mimicry is bound up with and altogether dependent u...

There are two agencies by which the pollen is carried to the pistil; first, by the wind, and, secondly, by insects (or, occasionally, by humming birds). Flowers that are fertili...

In order to understand the relation of Ontogeny to Phylogeny, it must be carefully borne in mind that the simple and lowly organized creatures on the globe at the first appearan...

On the theory that men in bygone ages were closely allied to simian creatures in habit as well as structure; that they led an arboreal life; and that, like the baby-monkeys to-d...

The view which teaches that psychic phenomena are correlated with the physiological phenomena of the brain; that these phenomena have undergone parallel[17] evolution, and “are...

Also it must be borne in mind that environment is a force of commanding influence. This environment (which the individual may make for himself to a limited extent) may be propit...

There is a broad septum between the nostrils. Their dentition is 2/2 1/1 3/3 2/2, and is distinctive, for the remaining Anthropoidea have 3/3 molars. The tail is long, hairy, an...

=El-as-mo-bran´chi-i= [Gr. _elasmos_, metal plate; _branchia_, gills.] Fish-like vertebrates which have no membrane bones in the skull or the shoulder-girdle; five pairs of stra...

[17] “Feelings and motions run parallel to each other, and where we do not meet with actual feelings we suppose the presence of the elements of feeling. But this parallelism wou...

A collection of bi-monthly publications, most of which are reprints of books published by The Open Court Publishing Company. Yearly, $1.50. Separate copies according to prices q...