a 
106 
not do, if they were confined at too great a 
depth when the water rofe higher. 
T have often obferved that when they were 
drawn out of their cells and put on the wet 
fand, they have chofe rather to creep out of 
the water, than go to the bottom under the 
fand. "This might poffibly be owing to the 
want of mud, and the warmth of the water, 
which is probably injurious to them. 
G. Hea 
Te BOOK 0 NAP URE on 
As to the food of thefe creatures, it is very 
difficultly difcovered, unlefs by the diffeGtion 
of them, which taught me that they live on 
clay or mud only. Whenever you open them, 
you will always find mud both in the ftomach 
and in the fmall and great guts. Thefe Worms 
are therefore in this refpect like the Moth, 
which feeds on the fame fubftance of which it 
makes its habitation. 
dues: Oy . 
How long the Vermicle or Worm of the Ephemerus is winged ; why it is called 
the efca or bait, and how long it hives. 
AVING confidered the egg, the Worm, 
and the food of the Ephemerus, the next 
thing is to fee for what {pace of time this Worm 
is fed or nourifhed: and though it feems a 
thing impracticable to determine how long 
any creature which lives in the earth under 
water is in feeding, yet this problem may be 
folved by confidering the different bignefs of 
thofe Worms which IT have beforementioned. 
Since the {malleft kinds of them, when fed 
for one year, in which time the largeft kind 
prepares to fly, is three quarters of a thumb’s 
breadth in length, and the middle fpecies is 
then only one half; it follows, that every 
Worm is feeding three years before it becomes 
fit to undergo its change, becaufe the largeft 
‘kind of Worms which begin this change, are 
two thumbs and a half long. 
The largeft day Worms when fully nourifh- 
ed or fed, regularly go out of their cells into 
the water, and thence afterwards rife into the 
air, as I fhallexplain hereafter. As every crea- 
ture has its enemy, thefe have many; the fith 
perfecute them immediately after they go into the 
water, inordér to undergo their change; and 
when this is accomplifhed and they rife out of 
the water into the air, the birds immediately 
bunt after and prey on them. This has been 
obferved by the failors, fifhermen, and others, 
who live near the Rhine, fo that they learned 
“from hence to ufe thofe little creatures as a bait 
to catch fith. 
Worms are called by the name of bait or bank- 
bait, near the village of Duerftede, Culenburg, 
and in other places. ‘This has likewife been 
the reafon that thefe creatures, when they 
afterwards began to fly, have been called by 
the name of the flying bait. But this creature 
~ is called Haft at Rotterdam, Schoonhoven, and 
Dordrecht, the moft ancient city in Holland, 
as foon as it becomes capable of fying. Hence 
has arifen the common proverb among the 
Dutch, “‘ Het iffer zoo dicht als haft,” to indi- 
cate a very numerous multitude, becaufe thefe 
little creatures at the times of their change, 
fly fo thick together in fwarms, that thay can 
no more be counted than the falling flakes of 
fnow. 
And hence it is that thefe’ 
Thefe Worms afford a very good bait for 
fifhing at any time of the year, if the weather 
be favourable for that purpofe; for fince they 
live three years in the mud before they are 
changed in fo wonderful a manner, like Silk- 
worms, into flying creatures, they may be eafily 
taken out of the banks at any time of the year 
for the fportman’s purpofe. But this cannot 
be conveniently done when the waters have 
rifen high, for it is then neceffary one fhould 
go naked into the water, which I have fome- 
times got done, that I might have an opportu- 
nity of inveftigating the nature and difpofition of 
thefe infects, and be able to examine anatomi- 
cally the internal patts. When the fithermen 
ufe this Worm, they fix the hook in the head, 
which is its hardeft and moft firm part. And 
as it is very long-lived, by the perpetual mo- 
tion it makes in the water, it becomes a very 
proper bait to allure the fith to fwallow the 
infidious hook. 
How very durable the lives of thefe Worms 
are I could thus form a judgment: I have 
fometimes pierced one of them with a little 
needle, in order to dry and preferve it when 
dead, but it has been ftill living the day after, 
though it had been a whole night in a little 
vefflel of urine, into which I had thrown it in 
order to kill it, But however tenacious they 
are of life, when they are taken out of their 
cells, and put into water mixed with clay they 
cannot live more than two days. ‘Therefore, 
whoever defires to keep thefe Worms alive 
ought to put them in nothing elfe but moift fand 
or wet clay. By this means I have known the 
largeft live four days, and the fmaller eight. But 
when they are all covered with water, they can- 
not by any means continue alive, for they mutt 
have air. 
If any one defires to fend thefe Worms 
abroad, the beft method is to tie together fome 
tubes made of the largeft bull-rufhes, and to put 
the Worms into them; for otherwife they can 
{carce be fent well, becaufe by running up and 
down at random, they hurt each other. By 
this method they may be likewife eafily carried 
to other rivers, as fifh are carried from one place 
to another. 
CoRrAtE: 
