ABSANCHIATA. 655 



FIRST FAMILY. Lumbricida, (Lat. lumlricus, an earth-worm.) 



The EARTH or ANGLE WORM has a body composed entirely 

 of numerous rings ; is of a reddish or bluish hue, and of a shin- 

 ing aspect. It secretes a viscous or glutinous substance which 

 protects the body and greatly facilitates its progress through the 

 earth. This worrn is enabled to creep at a good pace, by con- 

 trading and dilating its rings, the retractile bristles on the under 

 side of each ring assisting locomotion. The fore part of the 

 head in earth-worms acts as an awl in penetrating the earth, 

 which they loosen, enrich, and prepare for the labors of the 

 farmer by admitting the air and water. By their castings, which 

 so annoy the gardener, they, in a few years, cover a barren 

 waste with vegetable, or rather animal mould. Not improbably 

 every particle of earth in old pastures has passed through the 

 intestines of worms. They are known as coming to the surface 

 in wet weather and at night. The power of reproducing mu- 

 tilated parts is very great in this entire family, of which more 

 than twenty species have been described. The eggs are in cap- 

 sules, or membranous cocoons. Each egg produces two worms. 

 The species Lumbricus terrestris (Plate XVI. fig. 7b,) attains 

 nearly a foot in length, and has a hundred and twenty rings. 



SECOND FAMILY. Hirudinida, (Lat. hirudo, a leech.) LEECHES. 



These include various genera, both marine and fresh water. 

 All are without limbs or bristles, but have a sucker at each end 

 of the body, which enables them to move about and to adhere 

 to living bodies, penetrating the skin, by means of their three 

 jaws and teeth, and drawing the blood, upon which they were 

 formerly supposed to subsist.* Two species of Leech are al- 

 most exclusively medicinal ; the GREEN LEECH, Hirudo offici- 

 na.hs, and the BROWN LEECH, (spotted underneath,) H. medici- 

 nalis. Other species are, however, sometimes used. Fresh- 

 water leeches soon die after having been removed from the 

 water. Many leeches have eight eyes. There are several ma- 

 rine species which attach themselves to Torpedoes, Turtles and 



* It is very remarkable that blood is not the natural food of the Leech ; 

 and that the fluid which it so greedily swallows, does not pass into the 

 intestines, but remains in the stomach for many months, and what is still 

 more curious, it does not coagulate during' the whole of that time, as it 

 would do in an hour if exposed to the air, but continues to retain its fluid- 

 ity. (Gosse.) 



