species there still exist remnants of these lost toes.

The "glass-snake" looks very much like a cousin of the common garter snake. But it is not a snake at all. It is a lizard. And it is so classed in all the books.

Snakes are limbless lizards. When we find a lizard without legs, we call it a snake. And when we find a snake with legs, we call it a lizard. The "glass-snake" is a lizard because it has four legs. But its legs are not visible. They are internal. The "glass-snake" is a lizard on the way to becoming a snake. We catch it in the act. It is a connecting link between these two orders of reptiles. The legs have gone out of use, but not long enough ago for them to have passed out of existence. They are vestigial. In the bodies of some snakes, as the pythons and constrictors, there are little clawed remnants of hind limbs.

Snakes have only one lung. They have come from ancestors with two lungs, but their body is so narrow that there is not room for two lungs side by side, so one lung has been abandoned, and the other one has become larger by extending out along the body. The abandoned lung still exists, but it is a mere unused remnant.

The right ovary of birds has become atrophied in a similar way, all of the eggs of birds being produced by the left ovary. The ovary is the eggproducing organ of animals. In nearly all animals there are two ovaries, just as there are two kid

neys and two lungs. But in birds, for some reason, the right ovary does nothing, and has shriveled to a mere remnant.

In man and most other vertebrate animals there are two bones in the leg from the knee to the ankle -the tibia and the fibula. In birds and in some mammals there is but one bone (tibia), the fibula being represented by a mere splint extending down part way from the knee. You have probably seen this splint without recognizing it in the leg of the chicken. The big bone in the chicken's leg is the tibia; the splint is the vestigial fibula.

Insects ordinarily have two pairs of wings. But flies have only one pair, the hind pair being represented by a couple of knobs. In other species of insects the front wings are rudimentary. The male cockroach has two pairs of wings, and occasionally uses them in flying. But the female is flightless, the wings being rudimentary. The ovaries are vestigial in the working class of bees and ants. In the cow there are two teats that are rudimentary and four that produce milk. The rudimentary teats occasionally yield milk. In one breed of Chinese sheep the ears are mere vestiges, and in another breed the tail has dwindled to "a little button smothered in fat." In tailless dogs and cats there is a rudimentary stump. In some breeds of chickens the comb and wattles are rudimentary; and in the Cochin-China the spur has nearly disappeared. In the hornless breeds of sheep and cattle tiny knobs often grow out where

horns would naturally be; these are sometimes shed and grow again.

In many plants the petals and other parts of the flower are rudimentary. The purpose of the petals is to advertise the flower to insects by bright displays of color. In some flowers this is done by the stamens, while in others (the poinsettia, for instance) this advertising business has been taken over by the leaves adjacent to the flower. In the dandelion all of the outer florets have vestigial pistils. In some varieties of the cultivated gourd, which no longer lead the climbing life, the tendrils are rudimentary.

Parasitic animals and plants are commonly much degenerated, having abandoned entirely many of the organs which they had when they led a free and independent existence. Such organisms are, as a result, nearly always rich in ruins. The narwhal is a kind of whale that lives in the far north. It has only two teeth. They grow straight out in front. One of them grows to be six or eight feet long and is used in spearing its enemies and in breaking holes in the ice. The other one is vestigial, never projecting beyond the skull. In the pouched mice of Australia, the young are no longer carried in the pouch and the pouch has degenerated to a mere fold of skin on the abdo

men.

The so-called "wisdom teeth" in man are teeth which are in the act of passing out of existence. They appear late in life and in many persons do

not appear at all. There is a remnant of a "third eye-lid" in many animals at the inner corner of the eye. Man has this remnant, in common with many other animals. In birds, turtles, and other animals this third lid of the eye is in full use. It is the thin membrance that is pulled over the eye, often when the two ordinary eye-lids are open. In man and the man-like apes, the tail is vestigial, consisting of only three or four vertebrae much grown together. Before birth in all of these animals the tail is long and has muscles for wagging it. The bird's tail is also a mere remnant of what it once was. The oldest birds found fossil in the rocks had long tails composed of twenty vertebrae.

Vestigial structures are found everywhere. They are by-products of all organic evolution. There are vestigial instincts in the minds of men and other animals, and vestigial parts in all human laws, customs, and institutions. Our political, industrial, religious, educational, and legal institutions are full of vestigial features. This is a big subject. And if you will only get the key I am trying to give to you, you will be able to understand many things that are now mysteries to you.

3. Vestigial Instincts.

Useless instincts survive in the minds of men and other animals for the same reason exactly as useless organs survive in their bodies. Living beings are, as a rule, fitted to their surroundings,

not only in form and structure, but also in their natures and ways of acting. Animals have not only the organs and parts in their bodies which they need in order to enable them to live, but they have also the instincts to drive them to do the things they need to do in order to enable them to live successfully. Every being has a certain set of urges in its nature pushing it to do things, and these urges are generally useful. But when a species in the struggle for life is driven out of one set of surroundings into another set different from the first, it is likely to have some instincts and ways of acting that are not needed in the new environment. These useless instincts are called Vestigial Instincts.

Vestigial instincts are merely instincts which have been thrown out of employment by changes in conditions imposed by the struggle for life. Men and other animals have many ways of acting that are useless, just as they have many organs that are useless. These ways of acting survive wholly thru momentum acquired in times gone by. Like the vermiform appendix and the eyes of cave fishes, they have gone out of use, but have not yet gone out of existence.

Domesticated animals have been subjected to very great changes in surroundings, and they have, for this reason, an unusually large number of instincts that are useless. These instincts have been imported. They can be understood only by reference to the wild conditions in the midst of