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THE MUSEUM. 



Hair-worms. 



Anyone who will search carefully in 

 the waters . of a warm semi-stagnant 

 pool may be rewarded by seeing an or- 

 ganism resembling a long black thread, 

 so slender as to be almost invisible, 

 moving slowly, and apparantly aimless- 

 ly about, and propelling itself by 

 means of graceful convolutions of its 

 body. To the ignorant the organism 

 is a hair-worm; and by them it is be- 

 lieved to be a horse-hair, vivified by 

 long immersion. To the naturalist it 

 is a member of an interesting genera 

 {G or dins) of articulates. The study 

 of the life history of these animals is 

 exceedingly difficult on account of the 

 surprising metamorphoses which they 

 undergo. 



The adult hair-worm is about eigh- 

 teen inches in length. It is a herma- 

 phrodite and produces the remarkable 

 number of eight million eggs which are 

 all joined together and contained in a 

 long belt. This is rolled into a com- 

 pact ball about the size of a pea. The 

 worm then winds itself around the ball, 

 and, in the process ties itself into a 

 series of intricate knots. It retains 

 the ball of eggs in its coils until they 

 are hatched and float away; when, its 

 mission being ended it uncoils itself 

 and soon diss. 



The young worms, when they 

 emerge from the parent egg, are mi- 

 nute transparent bodies shaped like an 

 egg. One end is covered with sharp- 

 pointed hooks and the other with 

 short hair-like appendages called ver- 

 bratile cilia by means of which it 

 moves in a rotary direction, with con- 

 siderable rapidity through the water. 

 In this form the animals live, as near- 

 ly as can be ascertained, from twelve 



to eighteen days, at the e.xpiration of 

 which time, unless a grasshopper hap- 

 pens to jump into the water near them, 

 they perish. If, however, an unfor- 

 tunate grasshopper comes within their 

 reach, they stretch themselves, by 

 means of these hooks, to its legs. If 

 the grasshopper succeeds in escaping a 

 watery grave, the parasite escapes 

 with it. Otherwise, they; too, perish. 

 Upon emerging from the water, still 

 attached to the legs of the grasshopper 

 they burrow into its intestines where 

 they undergo their final transforma- 

 tion, emerging as perfect hair-worms. 

 Upon dry land the hair-worms move 

 slowly and with difficulty, but a slight 

 rainfall enables it to reach a pool 

 where it remains until the approach of 

 cold weather when it is believed to 

 burrow into the mud and lie dormant 

 until spring when it emerges to re-pro- 

 duce itself. It is believed to feed up- 

 on the animalculae, which with a pow- 

 erful microscope may be seen in water. 

 When we consider how few are the 

 chances of the worm at birth for reach- 

 ing maturity, we are not surprised 

 at the immense number of eggs 

 which each individual produces. 



Cyprare moneta. Money Cowry, front and back 

 view. A small oval species of yellowish- 

 white color; mainly from the Indian Ocean. 

 It is gathered largely by momen on the shore 

 of the Maldivian Islands, three days after the 

 full moon and before the new moon, being 

 thence transported to Africa where it is used 

 by the Natives for money. 



