162 Dispensatory of the United States. 



1. HiRUDo MEDiciNALis. Linn. ed.Gmel. I. 3095. — Sanguisuga 

 officinalis. Savigny. Moq. Tandon, Mon. Hir. p. 112, t. 6, f. 1. 

 The green leech. — Sanguisuga medicinalis. Savigny. Moq. Tan- 

 don, Mon. Hir. p. 114, t. 5, f. 2. The gray leech. 



Many of the best zoologists regard the Sanguisuga officinalis and 

 S. medicinalis of Savigny, as mere varieties.- They are both marked 

 with six longitudinal dorsal ferruginous stripes, the four lateral ones 

 being interrupted or tesselated with black spots. The color of the 

 back varies from a blackish to a grayish-green. The belly in the 

 first variety is of a yellowish-green color, free from spots, and bor- 

 dered with longitudinal black stripes. In the second, it is of a green 

 color, bordered and maculated with black. This leech varies from 

 two to three or four inches in length. It inhabits marshes and run- 

 ning streams, and is found abundantly throughout Europe. 



The great use made of leeches in the modern practice of medi- 

 cine, has occasioned them to become a considerable article of com- 

 merce. They are collected in Spain, France, Italy and Germany, 

 and exported in large numbers to London and Paris. They are 

 also frequently brought to this country, as the practitioners in some 

 of our large cities use only the foreign leech, although our own waters 

 furnish an inexhaustible supply of this useful worm. 



2, Hirudo decora. [Say. Major Long's Second Expedition, II. 

 268.) The medicinal leech of America has been described by Say, 

 under the name of Hirudo decora, in the appendix of the Second 

 Expedition of Major Long. Its back is of a deep pistachio green 

 color, with three longitudinal rows of square spots. These spots are 

 placed on every fifth ring, and are twenty two in number. The lat- 

 eral rows of spots are black, and the middle range of a light brown- 

 ish orange color. The belly is of the same color, variously and ir- 

 regularly spotted with black. The American leech sometimes at- 

 tains the length of four or five inches, although its usual length is 

 from two to three. It does not make so large and deep an incision 

 as the European leech, and draws less blood. 



The use of the indigenous leech is nearly restricted to the city of 

 Philadelphia. The practitioners of New York and Boston depend 

 for their supplies upon foreign countries, and leeching is seldom re- 

 sorted to in the southern or western states. Those which are used 

 in Philadelphia, are generally brought from Bucks and Berks county, 

 m Pennsylvania, and occasionally from other parts of the state. It 

 is estimated that from two hundred to two hundred and fifty thousand 

 are annually consumed. 



