170 CLASS-BOOK OF ZOOLOGY. 



SECTION XLV. 



5th Order — Long-bodied Worms : (Intestina, Lin.) 



§ 741. The Long-bodied Worms have long gelatinous 

 bodies, the skin of which is composed of jointed links, 

 and are without any external organ of motion ; as Leeches, 

 Earth-worms, and Intestinal Worms. 



§ 742. The Common Leech (Hirudo medicinalis) is one 

 linger in length and half a finger in thickness, of a dark- 

 ish color, with eight yellow, black, and red stripes above, 

 and with yellow spots below. It has ten eyes around the 

 head and mouth, with two rows of very minute teeth, with 

 which it opens the skin when it begins to suck. 



§ 743. Leeches are found in Europe, in brooks and 

 ponds, where they are very injurious to fish, which they 

 destroy by sucking their blood. They are an important 

 article of commerce, being extensively used as a substi- 

 tute for bleeding. 



§ 744. They can be easily raised in reservoirs made of 

 wood, where they propagate by their spawn : this, hard- 

 ening to a sponge-like bladder, splits after a short time on 

 one side, and the young ones come out. 



§ 745. The Earth-worm (Lumbricus terrestris) has a 

 mouth, but no eyes, is six inches or more long, and of the 

 thickness of a quill. It is of a red color, which deepens 

 in the middle, where is seen a tumor-like swelling. Its 

 body consists of 140 jointed links. 



§ 746. The ring-like accumulation in the middle, called 

 a saddle, is not a real tumor, but the breathing apparatus 

 of the animal, consisting of very minute gills. 



§ 747. The Earth-worm possesses great powers of re- 

 production. If the twenty-sixth part of one be cut off it 

 will become, within a few months, a perfect worm, as 

 long as the one from which it was severed. Its natural 

 increase is effected either by producing young ones, or 

 casting them off like buds. 



§ 748. The Portuguese Man-of-War (Holothuria phy- 

 ealis) is found in the Atlantic Ocean. Its body is about 



