26 HIRUDO. 



While at North Berwick, several years ago, I was informed that a 

 small pool on the summit of a rocky islet, Craigleith, at some distance 

 from the shore, abounded in the Medicinal Leech. Having obtained be- 

 tween twenty and thirty specimens, dwelling among thickish mud, all 

 proved on examination, to be the Horse Leech. They were rather under 

 middle size, none exceeding three inches in length, when animated by 

 the heat, for, although taken in the month of July, they were almost 

 torpid. 



About the same proportion of the Horse Leech may be taken from 

 under stones on the margin of a lake, as found in the water. 



PLATE III. 



FIG. 1 . Ifirudo sanguisuga, The Horse Leech ; back. 



2. Belly. 



3. Young specimen subsequently becoming green ; back. 



4. Belly. 



5. Head with ocular specks. 



6. Variety? back. 



7. Head with ocular specks. 



8. Variety ? quiescent. 



9. The same in motion. 

 10. The same enlarged. 



6. HIRUDO MEDICINALIS The Medicinal Leech* Plate III. fig. 11. 



Perhaps no animal of the known universe has contributed more to 

 alleviate the sufferings of mankind than the Medicinal Leech. Hence 

 its utility as the principal remedy in many distempers has been high 

 and permanent. 



* Mr Brightwell, an accomplished naturalist, observes, that the Medicinal Leech is 

 found occasionally in the neighbourhood of Norwich. Also that a dealer in leeches residing 

 in Norwich, keeps a stock of about 50,000 in two large tanks of water floored with soft 

 clay, wherein the animals burrow. Many capsules were found by Mr Brightwell deposited 

 by the leeches in the tanks, which the owner had always neglected or destroyed from igno- 

 rance of their nature. Brightwell on Hirudo geometrica, and some other species of British 

 Fresh- Water Leeches, Annals and Mag. of Nat. Hist., v. ix. p. 13. 



