APPENDIX. 307 



making a small opening, through which they endeavonr to force a 

 passage. I have frequently watched them, the head having free 

 motion without the capsule, using their utmost exertions to free 

 themselves ; but not being able to accomplish this, they have returned 

 to their former situation, renewing their efforts occasionally, until 

 their object was attained." — "At the time of birth they are nearly 

 colourless, and continue so for many months, with very little increase 

 as to size. They have the property of moving on the surface of the 

 water, with their belly uppermost. I have noticed nothing of this 

 nature in these animals when fully grown." 



Aulostoma gulo (page 46). 



Aldrovandus says, that in England this species is called " Blud- 

 sucker, Horseleche, vel Horselich, quod medeatur equorum cruribus : 

 nam Horse eisdem equus est : alii Lonuch Leache, Eliota anglus 

 scribit Horseleache, vel Blud Sucker." — Be Insect, hb. vii. p. 721. — 

 It continues to be called the Horse-Leech, and the vulgar retain also 

 the belief that the bite of it is venomous. Watson doubts the venom- 

 ous power of this leech. On the contrary, following his preceptor 

 Dr. Duncan {Edin. Disp. 463), he believes it might be used as well 

 as the medicinal leech, " nisi quod imposita cutem atrocius vulnerat, 

 et ad exugendum sanguinem alacrior est," p. 13. — A candidate for 

 the Doctorship, it might have been presumed, would have tried 

 whether this was a fact or not ; but it was easier to copy. And so 

 we are frightened with a tale that this leech adheres so firmly to the 

 limbs of boys — no doubt boys' blood is sweet — swimming in its 

 haunts, that it cannot be removed, — nay, the creatures may hide and 

 bury themselves in the skin, &c. — I have wondered how it comes 

 that French naturalists should quote this Thesis, which is really below 

 the average value of these productions, and is of no value. 



" Horsleches are wholesome to drawe foorthe foule blood, if thei 

 are put into a hollowe rede, and one of their endes cutte of, whereby 

 the blood maie run forthe." — Bulleiri, The Booke of Simples, 

 fol. Ixxxix. 



They believe, moreover, that the worm cannot be detached from 

 the skin of any victim ; and as their creed teaches them that the 

 blood flows from the posterior aperture as quickly as it is sucked in 

 by the mouth, danger and death are to be dreaded. The origin of 

 this belief is easily traced. There was (and is) a yearning wish, long 

 cherished with holy men, to identify every animal mentioned in 

 Scripture with some on« that was familiar to them, and could be 

 readily referred to in illustration of the text ; and hence our harmless 

 and insignificant worm stood as the representative of the horse-leech 

 which " hath two daughters, crying. Give, give ! " But the horse- 

 leech, which had such attributes assigned to it, and which I have 

 been censured for questioning, is unable to bite and draw blood. It 

 is, however, a cruel and greedy worm, feeding on earth-worms, grubs, 

 snails, other leeches, and on its own species, as Willoughby long ago 



