836 NATURAL HISTORY OF AQUATIC ANIMALS. 



depth of six to eight inches. Before the young appear, however, as many of the old ones as 

 possible are caught and transferred to other places. Otherwise they would consume too much of 

 the food required for the young. The young Leeches are fed upon the blood of living animals, 

 horses, cattle, etc., which are driven into the shallow water about twice a week and allowed to 

 remain a certain length of time. The Leeches attach themselves merely to the feet, but find in 

 those portions of their prey enough sustenance to cause them to grow rapidly and quickly attain 

 the required size. Fresh blood obtained from the slaughter-houses and deprived of its fibrine by 

 agitation is also supplied to them, or they are placed in it, while it is still warm, for a short time. 

 The feeding is carried on principally in September and October, and again in April and May. 

 During the winter the Leeches remain torpid at the bottom. 



Extravagant statements have sometimes been published as to the manner of feeding Leeches 

 in France. It is said that many of the owners of ponds are accustomed to buy up old and diseased 

 horses, drive them into the ponds, and allow them to be overcome by the Leeches, which fasten to 

 all parts of the body and kill them by a slow process of torture. This may occasionally take 

 place, but we are assured by one who has had considerable personal experience in the matter 

 that it is by no means a common practice. The quantity of blood sucked from the feet injures 

 the horses but little; and they are taken out in time to prevent harm. Some single breeding 

 establishments in Southern Europe cover an area of one hundred and twenty hectares. In about 

 three years' time, the young Leeches, without being .forced in their growth, attain a good medium 

 size and are suited to the wants of physicians. Medium Leeches are about two inches long, and 

 weigh three and one-half to four pounds to the thousand. The large Leeches weigh about five to 

 five and one-half pounds to the thousand, and this is the preferred size. The European Leeches 

 are graded in the markets as small, medium, and large. Only the medium and large Leeches are 

 used in this country. The very large ones, however, are generally considered too dangerous for 

 use, and are kept for breeding purposes. The foreign Leeches are transported and generally 

 stored in wooden cases or pails, containing swamp earth or mold. The American Leeches, how- 

 ever, are usually kept in glass vessels of water. 



American Leech ponds. Mr. Witte's ponds on Long Island, where he attempted the breeding 

 of American Leeches, occupied about three and one-half acres each, and were divided into five 

 compartments by ditches, like the French ponds. As before stated, his efforts were unsuccessful, 

 or at least unprotitably rewarded. In connection with these large ponds, Mr. Witte has since con- 

 structed thirteen others of much smaller size (about twelve by fifteen feet each) for the storage 

 and feeding of Leeches, which are generally imported in larger quantities than are required to 

 supply the immediate demands of the trade. He has had as many as one hundred thousand 

 Leeches in these small ponds at a time, but the number varies. 



Use of Leeches. Leeches are not now used nearly as much as formerly, and the practice of 

 leeching is gradually declining. From year to year the imports have constantly fallen off, and the 

 price of Leeches has rapidly decreased. Whether this will continue until the old custom of leech- 

 ing is entirely replaced by other methods of treatment or not cannot be predicted. It is evident, 

 however, that in Philadelphia the practice has greatly revived during the past few years, and the 

 best physicians are once more advocating the application of Leeches. About ten years ago thd 

 leeching practice reached its minimum in Philadelphia, and it has remained at a low stage until 

 very recently. A well-known Philadelphia leecher says that thirty or forty years ago many more 

 American Leeches were used in that city than European, but during the past year he has applied 

 only about one hundred of the former. Another leecher of the same city states that formerly he 

 applied on an average over three thousand American Leeches a year, while now he uses but a 

 -very few. 



