Page:Popular Science Monthly Volume 63.djvu/38

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34

POPULAR SCIENCE MONTHLY.

hunting and unsuccessfully hunted, until the approach of the dry season. Then as the stream dried up, it had taken to the last pool, and when this in turn had dried, the fish, like its neighboring friends and relatives, had burrowed deep into the thickening mud, rolled itself up into a ball, secreted a mass of mucus about its coiled body, and made ready for a summer 'sleep.' One of its first precautions was to keep its nose uppermost and to see that its 'breath' found a passageway out of its slimy capsule into the open burrow: in this way, then, it could breathe throughout the summer, while awaiting dormantly the return of rains, and the melting of its 'cocoon.' In this stage in its history it came to be dug up, and, together with other cocoons and their surrounding clods of earth, was crated and shipped to Europe. I am told that the shippers take pains to surround the crate with iron gauze to preserve the fish from the attacks of rats on shipboard, and that the clods of earth are disposed in such a way that the sides containing the breathing apertures face outward so that the imprisoned fish run the least possible danger of becoming stifled.

The present shipment came into the hands of Professor H. O. Forbes, Director of the Public Museums of Liverpool, and through his kindness the present specimen was donated to Columbia. A photograph, Fig. 1, shows the cocoon just as it came to the present writer. The tubular burrow through which the fish worked its way into the mud is seen conspicuously, and one may note that it was somewhat crooked, in spite of the fact that part of its margin has been broken away in the present specimen. Its usual length appears to depend upon the character of the bottom; from two to five inches are the measurements stated. At the end of the burrow lies the cocoon, a roundish mass, brown in color, paper-like in texture, but greatly roughened on its outer surface by attachment to rootlets and foreign matter. Its inner surface, as one would expect from the mucous nature of the shell, is found to be smooth and delicate. Where the cocoon meets the outer burrow its shell is somewhat flattened, and here, near the side, it is perforated by a delicate straw-like tube, formed of dry mucus, which passes downward into the mouth of the fish, and through this the fish respires during the dry season. It has, indeed, been shown by Professor W. N. Parker that this tube passes within the mouth of the fish and conducts the air to the entrance of the fish's lung.

In liberating the fish from the cocoon, the usual procedure is to allow the mass to remain in warmish water until the earth softens and melts, but in the present case a shorter, but somewhat more perilous, course was adopted. One side of the block was cautiously sliced away until the side of the papery cocoon became visible: then the earthy margins of the opening were carefully removed, so that the process of liberating the fish could be observed. The entire mass was next