THK AMI'.IMCAN MKDK'IN.M. I.KKCII. 



minute tentacles at the ml; the body is long, smooth, and tapers gradually to both ends, ami 

 the muscular system is very powerful, ami so arranged as to enable these Worms to roil them- 

 selves up into the shape (.fan open spiral, like a corkscrew, and then to rapidly rotate them-chcx 

 on the axis of the spiral. When the -h. up head is inserted into the loose mud or sand and the 

 body is thus rotated, it penetrates with great rapidity and disap|M>ars almost instantly, liolh 

 these species are t'ound on sandy as well as on muddy shores and flats near low-water mark, and 

 also in deeper water. The one usually most abundant is 7i. ililn-nnchidtux. This is readily distin- 

 guished by having a simple gill both on the upper and lower sides of the lateral appendages. 

 The other, It. nirri<-itnnx, has gills that arc more or less branched on the upper side of the 

 appendages, but none on the lower side; the appendages are also longer, es|M-<-ially posteriorly, 

 ami differently shaped. The proboscis is remarkably long and large, and when fully protruded it 

 shows four large, black, sharp, fang-like jaws or hooks. Both these Worms are destitute of true 

 bloodvessels, such as most of the allied Worms possess, but have the general cavity of the Ixxly 

 filled, between the various organs, with bright red blood, which shows through the skin, giving a 

 i or less red or purple color to the whole body and proboscis." 



The principal species of marine Worms which are used as bait are the Nereis vireii*, Herein 

 1iih<itti, l>i(>i>ti- ciijirea, Arenicola marina, Clymenella torquata, Marphyxa xaiiiiniiii-n, Arabella 

 t>l>alinn, and h'lii/iH-liobnhix dibranchiatux. 



The Karth Worm might also be mentioned in this connection, as it is likewise very commonly 

 used as a fish -bait, especially in fresh waters. All sportsmen, from boyhood up, are acquainted 

 with this simple form of bait, which is more easily obtained than any other. Large quantities arc 

 used annually, but no statistics can ever exist to determine the amount, which is irregularly 

 distributed over the country. 



234. THE LEECHES. 

 THE AMERICAN MEDICINAL LEECH MACROBDKLLA DECOBA, Vernll. 



Structure of teeche*. In the true Leeches, which belong to the order Hirvdinca, the body is 

 flattened, divided into numerous short and indistinctly marked segments, and bears neither bristles 

 nor appendages of any kind. The head is small, with five pairs of minute, simple eyes, and each 

 end of the body terminates in a sucker. "The mouth is armed internally with three pharyngeal 

 teeth arranged in a triradial manner, so that the wound made in the flesh of i>ersons to whom tin- 

 Leech is applied consists of three short, deep gashes radiating from a common center." The 

 stomach is large, and the nervous system consists of a "brain" and ventral cord. The Leech is 

 hermaphroditic. The eggs, which range from six to fifteen in number, are contained in a sort of 

 spongy, slimy cocoon, from half an inch to an inch in diameter. These are deposited near the 

 \\ ater's edge and hatched by the heat of the sun. Respiration in the Leeches is carried on through 

 small ai>ertures arranged along the under surface of the body. The Leech swims with a vertical 

 undulatory motion and moves both in and out of the water by means of ite suckers, fastening itself 

 first by one and then by the other, and alternately stretching out and contracting it* body. 



There are two or three species of Leeches, known as medicinal Leeches, which afford the 

 most convenient means of drawing blood from the human body. They have been used by 

 physicians for this purpose for many years, and have given rise to a very extensive and profitable 

 trade. One of the species belongs to North America. 



Distribution and xtructure of the American Leech. Although numerous species of Leeches 

 abound in the fresh waters of the United States and are related to the fisheries in various ways, 

 ft3 F 



