CLASS-BOOK OF ZOOLOGY. 159 



for examination by taking some of the water and pour- 

 ing it into tumblers. After a short time the Polypes will 

 be seen attached to the glass. 



§ 678. The body of the Polype is as thick as a quill, 

 and one inch long, with from six to twelve arms of the 

 same length, which will be seen hanging down from the 

 glass, on which it sticks with the imperforated extremity. 

 It moves in the same manner as a Leech. 



5 679. The construction of the Polype, and its reproduc- 

 tion, are very astonishing ; for being merely a gelatinous 

 open channel, it has no intestines, and may be turned 

 inside out without the least injury ; besides, it may be cut 

 into many pieces, and each piece, after a few days, will 

 become a new Polype. 



§ 680. These Polypes are green or brown, black or red, 

 and can be kept alive more than two years, if they are 

 fed with earth-worms, plant-lice, or very small fishes. 

 The manner in which the Polype seizes, with its arms, 

 the substance on wmich it feeds, will excite the admira- 

 tion of the student of Natural History. 



§ 681. The Sea-blubber (Medusa) has a gelatinous 

 naked body, generally round like a ball, interwoven with 

 arteries for the purpose of sucking water ; and having 

 on the sides a number of thread-like organs, or arms, for 

 seizing its prey and conveying it to its mouth, which is 

 in the*central part of its body. 



• 682. These animals, which are of a beautiful bluish- 

 white color, vary in size and form. They are frequently 

 seen in the tropics, floating on the surface of the sea. 

 As they are almost motionless, they are often driven by 

 winds and waves on the shores, where they soon dissolve, 

 and dry up to a mere membrane. 



\ 68*3. Sea-blubbers are of no use to man. Their 

 touch produces red spots on the skin, and causes an un- 

 pleasant feeling, like the sting of a nettle. They are 

 often observed at night, skimming over the water, and 

 shining with the most beautiful variegated colors. 



It is not improbable that several of these species are 

 the principal ingredients of which the edible birds-nests 

 are made. 



