THE LEECHES 



3415 



in France, Germany, England, Russia, and Sweden. Another nearly allied spe- 

 cies, H. officinalis, which is of an oiive-green, unspotted color, is most abundant 

 in the south and southeast of Europe. Other kinds are found in Morocco, 

 Senegal, India, and North America. In some parts of the Tropics, such as India 

 and Ceylon, land leeches, which abound in meadows and woods, are a terrible 

 plague. They live on grass or trees, are exceedingly quick in their movements, 

 scent prey from a long distance, and troop in numbers to the spot. Hence a person 

 brushing through the jungle becomes covered with them, unless some precautions 

 are taken. 



Another well-known member of the group is the horse leech (Aulostoma gulo) , 

 characterized by its blackish green color, the great narrowing of the fore part of 

 the body, and the presence of only three small teeth in the mouth. Many stories 

 are current as to the dangerous nature of these leeches, and it is even said that nine 

 of them will suck a horse to death; but although doubtless a voracious creature, it 

 is certain that such accounts are fallacious. The horse leech lives on earthworms, 

 snails, grubs, and other leeches, and even creeps into the shells of fresh-water 



STRUCTURE OF I.EECH. 



I. Alimentary canal a. CEsophagus ; b. Saccular stomach ; c. I,ast pair of pouches. 

 2. Anterior end, showing eyes. 3. Jaw. 



mussels, and takes up a lodging there until it has devoured the inmate. Another 

 form that abounds in fresh-water ponds and streams is Nephelis vulgaris, which 

 reaches a length of nearly two inches, and has four pairs of eyes and toothless jaws. 

 It appears to feed partly on animal and partly on vegetable food. A second group 

 of the leeches are the Clepsinidce, recognized by the short flat body, which toward 

 the front is usually stumpy, and ends in a seizing disc carrying the eyes. The 

 gullet, which is toothless, can be protruded like a proboscis. Different species of 

 the genus Clepsine may be found on the leaves of water plants and on the under 

 side of stones. They are gray, yellow, or whitish in color. Instead of burying 

 their eggs like the medicinal leech, these creatures carry them about, and the young 

 after birth remain some time with their mother. They live principally upon water 

 snails and young mussels. The engraving on p. 3416 represents the rock leech, 

 Pontobdella muricata, remarkable for being an inhabitant of the sea, and also for 

 having the skin covered with warts and knobs. The body, which gradually nar- 

 rows from the posterior end to the head is of a greenish gray color, and the ante- 

 rior sucker large and button shaped. During the daytime these leeches usually rest 



