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THE COMMON EARTH -WORM. 



Another species, the Porcupine Sea-mouse, is easily distinguished from the preceding 

 creature by the peculiar structure of the back, which is devoid of the felt-like substance, 

 and the scales are consequently bare. 



On account of the singular structure of the 

 Ch^etopteris, it has been placed in a family by 

 itself, of which it constitutes the sole genus. 



This remarkable worm is one of the tube- 

 builders, and makes a dwelling of a tough parch- 

 ment-like consistency, measuring eight or ten 

 inches in length. If is found in the seas about 

 the Antilles. As maybe seen by reference to the 

 engraving, in this curious being there is no distinct 

 head, and no vestige of maxilla 1 , but the proboscis 

 is furnished with a lip, to which are attached two 

 small tentacles. "Then comes a disc with nine 

 pairs of feet, then a pair of long silky bundles, 

 like two wings. The gills, in the form of laniina>, 

 are attached rather below than above, and pre- 

 dominate along the middle of the body." In the 

 illustration the animal is represented in its natural 

 size. 



The next family, of which the common Earth- 

 wobm is a very familiar example, is distinguished 

 by the ringed body without any gills or feet, but 

 with bristles arranged upon the rings for the 

 purpose of progression. 



In the well-known Earth-worm, the bristles 

 are short and very stiff, and are eight in number 

 on each ring, two pairs being placed on each side; 

 so that, in fact, there are eight longitudinal rows 

 of bristles on the body, four on the sides, and four 

 below, which enable the creature to take a firm hold 

 of the ground as it proceeds. 



Except that the worm makes use of bristles, 

 and the snake of the edges of its scales, the mode 

 of progress is much the same in both cases. The 

 whole body of the creature is very elastic, and 

 capable of being extended or contracted to a won 

 derful degree. When it wishes to advance, it 



pushes forward its body, permits the bristles to hitch against the ground, and then, by 

 contracting the rings together," brings itself forward, and is ready for another step. As in 

 each full-grown Earth-worm there are at least one hundred and twenty rings, and each 

 ring contains eight bristles, it may be imagined that the hold upon the ground is very 

 strong. 



As every one knows, the Earth-worm lives a very solitary life below ground, driving its 

 little tunnels in all directions, and never seeing its friends, except at night, when it comes 

 cautiously to the surface and searches for company. Tn the evening, if the observer be 

 furnished with a "bull's-eye" lantern, and will examine the ground with a very gentle and 

 cautious step, he will be sure to find many worms stretching themselves out of their holes, 

 retaining for the most part their hold of the place of repose by a ring or two still left in the 

 hole, and elongating themselves to an almost incredible extent. If, while thus employed, an 

 Earth-worm be alarmed or touched, it springs back into its hole as if it had been a string of 

 india-rubber that had been stretched and was suddenly released. 



( ILETi )!• I'BRUS. ' liretoptmis pergament&ceus. 



