Page:Popular Science Monthly Volume 50.djvu/68

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56
POPULAR SCIENCE MONTHLY.

eled out of the white layer and rests on a colored groundwork, blue, pale salmon, etc.

A very strange little fellow is Rhizochilus antipatharum. In his youth he has a well-formed shell, but as he grows older he cements about it bits of coral, other shells, and anything which he finds convenient, until the opening is entirely closed, and he can communicate with the outer world only by means of his siphon.

One of the largest shells found on the coasts of the northern and middle Atlantic States is Scycotypus canaliculatus. It is protected from injury by its coat of rough brown fur. The inhabitant comes ashore to lay her eggs, which are a great curiosity. There are hundreds of little leaf-like sacs which contain the eggs, all joined together, forming a long chain.

Æons ago the shells had very different forms from those of to-day, but we have left a few members of the group which existed in countless millions. The nautilus of the present time is not a very distant relative of the ammonites, which we find so marvelously preserved in the Silurian deposit, every line and penciling absolutely perfect.

Note.—I am greatly indebted to Prof. J. S. Kingsley, who was my teacher of biology at Tufts College, for his assistance to me when I was studying the shells, and for material in this sketch taken from his article on Mollusca in the Standard Natural History.
 

THE EMPLOYMENT OF THE MOTOR ACTIVITIES IN TEACHING.
By Prof. EDWARD R. SHAW, Ph. D.,

DEAN OF THE FACULTY OF PEDAGOGY, NEW YORK UNIVERSITY.

THE recent development of our knowledge of the nervous mechanism in its relation to the processes of education leads us to appreciate the great worth of the ideas advanced by two educators of the last century, Basedow and Heusinger, and also to see quite clearly the great advantage which will result in the work of the school from the applications of the truths set forth by them.

When Basedow said that children were fond of noise and movement, that they hated to sit still for a long time, that a continued strain of attention and learning by rote were distasteful to them, and that only by force could they be trained to such vexatious employments, he apprehended a truth upon which the researches of recent years have given us more specific knowledge; and his warning that through the disregard of this principle not only the health of the pupils is weakened, but also their intellect