Page:Popular Science Monthly Volume 63.djvu/41

Rh. This limb, by the way, has lost its tip, and is being regenerated, the lighter portion, as shown in the figure, having already been grown. I might note that at the point where the injury occurred a small transverse branch later made its appearance, but after this had grown for a year or two and become one eighth of an inch in diameter, it gradually degenerated and finally entirely disappeared. A characteristic movement is illustrated in Fig. 5; here the fish, having reached the end of the tank, draws back before turning in another direction. To accomplish this result, the fins again operate in a quadrupedal fashion: pressing on the limbs firmly, the fish recoils, pushing itself back by means of its shoulder and pelvic muscles, the tail and body taking little or no part in the process. In this figure we again note the strain which is laid upon an extremity, for the left arm is bent almost to the shoulder.

Another characteristic movement is pictured in Fig. 6, where the animal is circling around. The weight of the hinder body is supported firmly by the outstretched legs, and the arms swing forward and backward, turning the anterior part of the body. In the present position the animal is on the point of again advancing, and in this event the limbs will move alternately as shown in Fig. 4. Throughout these varied movements the fish is slow and deliberate, reminding one rather of a newt than of a fish. In the present figures attention should be called to the great length of the uninjured arm, which in this small specimen indicates doubtless a larval feature of the fish. Also noteworthy is the position of the external gills, which stand out at the sides of the head very much as they do in a larval salamander.

From this stage onward the life of the lung-fish was a rather uneventful one. It received its daily diet of earthworms with apparent relish, and upon them it thrived and grew. Its yearly increase in size varied between two and three inches; at the time of its death it measured eighteen inches. Its movements in the aquarium were like those of larval salamanders, axolotl, for example. Only on rare occasions did it swim in a fish-like manner by means of caudal fin and undulating body, and only twice a year did it show of what sudden movements and great activity it was capable. On these occasions it was taken from the tank and carried to or from the New York Aquarium where, through the courtesy of the officials, it was kept during the summer. Cold weather, as might be inferred, it was least capable of enduring. On several occasions during winters, when the temperature in the aquarium room became less than 50° F., the fish was found in a semi-torpid condition. It was then taken out and handled with scarcely a movement, but was revived by immersion in warm water. It gave its attendant no uneasiness on the score of appetite, for it took its food with clock-like regularity. Its great difficulty, however, appeared