812 
«« When agreat many of these fishes are thus 
adhering at once to the sides of a ship, they 
may in some degree retard its mation, by pre- 
venting its easy passage through the water, in 
the same manner as any other extraneous sub- 
$tances are known to do; nor can it be 
thought improbable that the adhesion’ of 
these fishes in considerable numbers to the 
side of asmall canoe in the earlier ages of 
mankind, may have operated still more pow- 
erfully, and not only have impeded its pro- 
gress, but even have caused it to iucline to- 
wards one side ; and the tale once related, 
might have gradually grown into the exagge- 
rated powers afterwards ascribed to the animal, 
«* A second reason of the remora’s thus at- 
taching itself to the larger fishes and to ves- 
sels is, that it may be im readiness to avail 
itself of the occasional remains of the prey of 
the former, or of the oflals thrown out from 
the latter ; being naturally voracious, and by 
no means delicate in its choice, and frequent- 
ly following vessels in great numbers in order 
fo obtain occasional supplies of food. The 
remora also, especially in stormy weather, ad- 
heres to’ rocks, like the lump-fish and some 
others. — 
«© The remora fs principally an inhabitant of 
the Mediterranean and Atlantic seas. Its ge- 
Yeral colour is an uniform brown, without 
any material difference of shade either on the 
upper or lower surface. Itsometimes how- 
ever varies in colour, and Commerson assures 
us that when a great number of these fishes 
are attached either to the side of a vessel or 
to a large fish, itis not very uncommon to see 
one or two which differ from the rest in being 
of a whitish colour. ‘The skin is smoo:h 
and destitute of scales, but marked with nu- 
merous impressed points or pores ; the mouth 
js large, and furnished with very numerous 
small teeth; and the lower jaw is rather 
longer than the upper: the eyes are small, 
with vellow irides: the lateral line com- 
mences above the pectoral fins, and from 
thence pretty suddenly descending, runs 
straight in the tail, which is of a slightly 
forked, or rather lunated form. ‘The nuinber 
of transverse divisions on the shield of this 
species varies from sixteen to twenty, but the 
most general number is eighteen. ‘The fish 
grows to the length of about eighteen inches.” 
Dr. Shaw seems to attribute the adhe- 
sive power to the fringe of perpendicu- 
lar teeth or filaments on the edge of each 
partition. We strongly suspect tbat the 
effect is to be accounted for on the prin- 
ciples of pneumatics, and that the appa- 
ratus, in its general manner of operation, 
is similar to a simple amusement of 
children, which consists in raising up a 
stone by the means of a sing fastened 
to the middle of a piece of wet leather. 
If the filaments were of a glutinous na- 
ture, and the whole of the tenacity arise 
from that circumstance, it is not easy to 
NATURAL HISTORY. 
conceive how the animal could »readily 
disengage itself at pleasure; or how, in 
consequence of a force laterally directed, 
it should slide with: comparatively so 
much ease on the body to which it is 
attached. The remora, we apprehends 
previously to its adhesion, diminishes the 
breadth of its shield by a muscular cons 
traction of the dissepiments or partitions; 
so as to fill up the intermediate furrows, 
and to form a plane surface in close cons 
tact at all points with the substance on 
which it is about to fix. It then instantly 
restores its shield to its former state, and 
each furrow becomes nearly a vacuum, 
on which the external air and water 
piesses with a force, greater or less, in 
proportion to the dimensions of the in- 
tervening surface. The use of the fringe 
of filaments is probably to let in the 
air or water by a similar muscular con 
traction, and at once to remove the cause 
of the adhesion. The common goby, and 
perhaps all the gobies may adhere to 
rocks, and set themselves at liberty, by a 
similar contraction and dilatation of the 
funnel shaped central fins. 
Mr. Pennant asserts in his British Zoos 
logy, that the tunny frequents our coasts, 
but not in shoals like the tunnies of the 
Mediterranean ; and that they are not wn- 
common in the lochs on the western coast 
of Scotland, where they come in pursuit 
of herrings, and often during night strike 
into thenets and do much damage. Dr. 
Shaw, though he quotes Mr. Pennant, 
and does not dispute his authority, ap- 
pears to think them of less frequent oc- 
curience, and speaks of them as acci+ 
dental stragglers. Such we have reason 
to believe is the case. In the summer of 
1801, we ourselves happened to be at 
Inverary in the height of the herring 
fishery, which that year was remarkably 
abundant, and enquired of an old fisher- 
man whether any tunnies had been lately 
taken, with a faint hope that we might _ 
be fortunate enough to obtain a sight of 
this rare British fish. He did not know 
it by the name of mackrel sture, which 
Mr. Pennant says it bears in the west of » 
Scotland, but on a little farther expla- . 
nation recognized jt as what he called an 
overgrown mackrel, and said that one 
was taken in Loch Fine about 30 years 
before, of five or six hundred weight, but 
that hehad not heard of any inthe Loch 
since. Mr. Pennant was there in 1769, 
and probably saw the same fish; or se- 
veral stragglers might have accidentally | 
wandered to the same coasts about the 
