HIRUDO. 5 
The firm adhesion of the sucker to the skin of its prey must render 
this animal a cruel and inveterate ememy. It is seldom detached by the 
fishermen without suffering injury ; but when adhering to hard substances, 
by inverting, it may be removed with comparative facility, by inserting 
the edge of the thumb nail evadually under the sucker. 
During the day this singular leech reposes in absolute quiescence, but 
towards evening, its wonted coil relaxes in wider curves, and it rears 
itself erect on the plane of position, with the head turned inwards. 
The quiescence of a solitary specimen, however, is interrupted by the 
introduction of stranger leeches of its own kind; their society is evident- 
ly gratifying. Five having been collected in the same vessel, all began 
to intertwine their necks together after fixing the sucker ; they stretched 
and curved, or contracted the body, yet without shifting from their re- 
spective spots of adhesion. Such movements continued for hours. 
Meantime, small and almost transparent vesicles, as it appeared, 
each formed like a grain of oats, were observed protruding from the neck 
of the animal. These extended about three lines ; each being connected 
to the neck by a slender filament, also transparent. Two milk-white 
parallel oblong substances were exposed within. 
The number of these vesicles is variable, according to the specimen. 
In each of two a vesicle issued from that ring of the neck which was 
next the lowest ; each of two others had three.—In one of the leeches, 
two vesicles, in near approximation, issued from the fifth or sixth row of 
tubercles, lower than the neck. At first three appeared in the second 
leech : and six or seven, some days later, whereof four then issued from 
the neck. On the day subsequent, they seemed to have increased to 
nine or ten. About five such objects were protruding from the neck of 
a middle-sized specimen of the leech, on the day after being committed 
to the vessel of a previous occupant ; and from the neck of its companion, 
two of the same kind, appearing flaccid, which might have been mistaken 
for two short horns. 
Authors have ascribed two short horns to the Skate Leech, under 
which specific character, indeed, it stands in the Linnean Systema Na- 
ture. Farther, it is thus represented in Barsut's Genera Vermium,— 
