84 HIRUDINEA OR LEECHES. 



mature they seem to require the blood of the warm-blooded 

 animals for nourishment. 



The Horse-Leech (H^mopis sanguisuga). 



The horse-leech has an elongated body contracted in front, 

 widest in the middle, and with a sucker at each extremity. It 

 is composed of from 95 to 100 rings. They copulate much as 



Fia. 30. — The Hobse-Leech (Ho'-mppiR sanguisuga). Eailliet. Natural size, 

 and youug leech. (From Neumann, Par. Dis. Ani.) 



described in the case of the earthworms. There is also a girdle 

 or sexual band produced. The ova are laid about forty days 

 after fecundation. When ovipositing, this leech, like the 

 Medical Leech {H. medicinalis), burrows into damp ground 

 and lays about fifteen ova in the funnel-shaped case secreted by 

 the girdle. This case is left by the worm, and hardens and 

 forms a brown spongy cocoon. Each leech may form two of 

 these cocoons. The ova take from twenty to thirty days to 

 incubate. The young leeches are filiform, and remain near the 

 case for some days, using it as a kind of shelter. 



This species attacks horses as they come to drink, each 

 individual witlidrawing as much as one and a half drachm 

 of blood from the wound they make with their* mouth. Often 

 one may see blood flowing from the wound after the leech 

 has fallen off' its victim, gorged with food. There is some fluid 

 in the pharynx which prevents the blood from coagulating 



