30 HIRUDO. 



grass or humectation ; and they are distributed in Edinburgh and the 

 neighbourhood, or even at some distance, in chip boxes. 



Of late, however, an extensive dealer has established himself in this 

 city, to the great convenience of the public. 



A considerable traffic in leeches has recently sprung up between 

 France and the province of Constantine in Africa. They are carried by 

 the native Arabs in earthen vessels to the city of that name, and sold 

 there at the rate of about- half a guinea per thousand. The amount of 

 this branch of trade is computed at 12,000 or 13,000 annually. 



PLATE III. 



FIG. 1 1 . Hirudo medicinalis. 



7. HIRUDO COMPLANATA Glossipora tuberculata. Dr James Rawlins 

 Johnson. Plate IV. fig. 1. 



It must be certainly accounted very absurd, though proposed by one 

 of our most distinguished naturalists, to change the name, sufficiently 

 established, of an animal, because some spot, wart, or tubercle, or a 

 few additional stripes or hairs, happen to- be observed which were pre- 

 viously unnoticed. Therefore I prefer as explicit enough, the name 

 formerly bestowed on the present subject. 



The Hirudo complanata, or flattened leech, extends an inch and a 

 half in motion, and nine lines when at rest. It is comparatively thin, 

 the body resembling the outer longitudinal section of a pear. Instead 

 of the soft and flexible consistence of the preceding leeches, the body is 

 rigid, and the skin somewhat hard, so that certain observers have as- 

 cribed a crustaceous character to it ; neither does the animal swim. It 

 is remarkably quiescent, its motion always slow, and effected by bring- 

 ing the sucker and the head in juxtaposition, when the head being re- 

 lieved, is secured as a farther advance, and being secured again, the 



