Page:Popular Science Monthly Volume 42.djvu/778

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THE POPULAR SCIENCE MONTHLY.

respiration, but they are of the utmost utility in the function which comes next to respiration in importance—namely, that of nutrition. The animal has to be fed, and all the arrangements of the limbs are more or less subservient to this primary object. In a fish the muscular masses at both sides of the spine bend the posterior part of the body and the tail alternately to one side or another, and so the animal is propelled through the water in search of food. No doubt these same muscles help it to escape danger, but their primary object is to obtain food; and if there be great hunger all animals will strive to feed, whatever be the risk they run in doing so. The movements of fish are simple compared

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PSM V42 D778 Diagram of the motor centres of the brain.jpg
Fig. 9.—Diagram of the Motor Centers in the Brain. (Modified from those of Ferrier and Horsley.) The motor centers have been numbered so as to represent the successive actions in seeing, taking, and eating the apple, etc.: 1. Eve sees the fruit (eyes turn to opposite side). 2. Looks more eagerly at it (head and eyes turn). 3. Turns toward it (head to opposite side). 4. Puts forth her hand to take it (a, movements of shoulder; b, of elbow; c, of wrist; d, of fingers). 5. Luxuriously shuts her eyes, so as to enjoy the sweet morsel more thoroughly. 6. Eats the apple. 7. Picks out and throws away the refuse (d, movements of fingers; e, of index; f, of thumb; a, b, c, as in 5). 8, 9, 10, 11. Went and got another for Adam (8, movements of hallux; 9, of small toes; 10, of knee and ankle; 11, of hip).

with those of animals with limbs, and especially with those of man. Yet the arrangements of man's body are equally adapted with those of the fish for obtaining food.

There are two prevalent ideas regarding the origin of man. One is that he started full grown and perfectly developed from the dust of the ground, and lived in a garden which he "dressed and kept." The other is the Darwinian one, that man is developed from an arboreal animal like the monkey, though lower than the monkey. It matters not which of these ideas we take, because they perfectly agree that primitive man lived at first in a kind of paradise where he was not exposed to the attacks of wild beasts, and where he fed on the fruit which he plucked from the trees around him. The story of Adam and Eve has got the advantage of not only being more poetical, but it is very much