5-32 
aised from slips and cuttings; and some late 
observations have shown, that there are some 
, animals whi'ch have the same property. The 
polype (see Polypus) was the hrst inst nee 
we had of this ; but we had scarcely time to 
wonder at the discovery Mr. Trembley had 
made, when Mr. Bonelt discovered the same 
pioperty in a species of water-worm. Amongst 
the plants which may be raised from cuttings, 
there are some which seem to posssess this 
quality in so eminent a degree, that the 
smallest portion ot them will become a com- 
plete tree again. 
It deserves inquiry, whether this reproduc- 
tion wall or will not take place in whatever 
part the worm is cut ? In order to try this, 
J'lr. Bonett entered on a course of many ex- 
periments on the water-worms which have 
this property. These are, at their common 
growth, from two to three inches long, and 
of a brownish colour, with a cast of reddish. 
From one of these worms he cut oil the head 
and tail, taking from each extremity only a 
small piece of a twelfth of an inch in length ; 
but neither of these pieces was able to re- 
produce what was wanting. They both pe- 
rished in about 24 hours ; the tail lirst, and 
afterw ards the head. As to the body of the 
worm from which these pieces were separat- 
ed, it lived as well as before, and seemed in- 
deed to suffer nothing by the loss, the head- 
part being immediately used as if the head 
was on, boring the creature’s way into the 
mud. There are, besides this, two other 
points in which the reproduction will not take 
place ; the one ot these is about the filth or 
sixth ring from the head, and the other at the 
same distance from the tail ; and in all proba- 
bility the condition of the great artery in 
these parts is the cause of this. 
What is said of the want of the reproduc- 
tive pow er of these parts, relates only to the 
head and tail ends; for, as to the body, it 
feels very little inconvenience from the loss 
of what is taken off, and very speedily re- 
produces those parts. Where then does t he 
principle of life reside in such worms, which, 
alter having their heads cut off, will have not 
only the same motions, but even the inclina- 
tions, that they had before? And yet this dif- 
ficulty is very small, compared to several 
others. Is this wonderful reproduction of parts 
only a natural consequence of the laws of 
motion; or is there lodged in the body of 
the creature a chain of minute buds or shoots, 
a sort of little embryos, already formed, and 
J^ced in such parts where the reproductions 
are to begin ? Are these worms only mere 
machines, or are they, like more perfect ani- 
mals, a sort of compound, the springs of 
whose motions are actuated or regulated by 
a sort of soul ? And if they have themselves 
such a principle, how is it that this principle 
is multiplied, and is found in every separate 
piece ? Are we to believe with Malpighi, that 
these sorts of worms are all heart and brain 
from one end to the other ? This may be ; 
but yet if we knew that it was so, we should 
know in reality hut very little the more for 
knowing it: and it seems, after all, that, in 
cases of this kind, we are only to admire the 
works of the great Creator, and sit down in 
silence. 
The nice sense of feeling in spiders has 
been much talked of by naturalists ; but it 
appears that these worms have yet some- 
what more surprising in them in regard to 
REPRODUCTION. 
this particular. If a piece of stick, or any 
other substance, is brought near them, they 
do not stay for its touching them, but begin 
to leap and frisk about as soon as it comes 
towards them. There want, however, some 
further experiments to ascertain whether this 
is really owing to feeling or sight ; for though 
we can discover no distinct organs of sight in 
these creatures, yet they seem affected by 
the light of the sun or a candle, and always 
frisk about in the same manner at the ap- 
proach of either; nay, even the moonlight 
has some effect upon them. 
A twig of willow, poplar, or many other 
trees, being planted in the earth, takes root, 
and becomes a tree, every piece of which 
will in the same manner produce other trees. 
I lie case is the same with these worms; they 
are cut to pieces, and these several pieces 
become perfect animals; and each of these 
may be again cut into a number of pieces, 
each of which will in the same manner pro- 
duce an animal. It has been supposed by 
some that these w'orms were oviparous ; but 
Mr. Bonett, on cutting one of them to pieces, 
having observed a slender substance, re- 
sembling a small filament, to move at the end 
ol one of the pieces, separated it; and on 
examining it with glasses, found it to be a 
perfect worm, of the same form with its pa- 
rent, which lived and grew larger in a vessel 
of water into which he put it. These small 
bodies are easily divided, and very readily 
complete themselves again, a day usually 
serving for the production of a head to the 
part that wants one ; and, in general, the smaller 
and more slender the worms are, the sooner 
they complete themselves after this opera- 
tion. When the bodies of the large worms 
are examined by the microscope, it is very 
easy to see the appearance of the young 
worms alive, and moving about within them ; 
but it requires great precision and exactness 
to be certain of this ; since the ramifications 
of the great artery have very much the ap- 
pearance of young worms, and they are kept 
in a sort of continual motion by the systoles 
and diastoles of the several portions of the 
artery, which serve as so many hearts. It is 
very certain, that what we force in regard to 
these animals by our operations, is done also 
naturally every day in the brooks and ditches 
where they live. A curious observer will 
find in these places many of them without 
heads or tails, and some without either ; as 
also other fragments of various kinds, all 
which are then in the act of completing them- 
selves; but whether accidents have reduced 
them to this state, or they thus purposely 
throw off parts of their own body for the re- 
production of more animals, it is not easy to 
determine. They are plainly liable to many 
accidents, by which they lose the several 
parts of their body, and must perish very 
early if they had not a power of reproducing 
what was lost ; they often are broken into 
two pieces, by the resistance of some hard 
piece of mud which they enter ; and they 
are subject to a disease, a kind of gangrene, 
rotting off the several parts of their bodies, 
and must inevitably perish by it, had they 
not this surprising property. 
I his worm was a second instance, after the 
polype, ot the surprising power in an animal 
of recovering its most essential parts when 
lost. But nature does not seem to have 
limited her beneficence in this respect to 
these two creatures. Mr. Bonett tried the 
same experiments on another species of wa- 
ter-worm, differing from the former in being 
much thicker. This kind of worm, whei> 
divided in the summer season, very often 
shows tiie same property; for if it is cut into 
three or four pieces, the pieces will lie like 
dead lor a long time, but afterwards will 
move about again; and will be found in this 
state of rest to have recovered a head, or a 
tail, or both. After recovering their parts, 
they move very little; and according to this 
gentleman’s experiments, seldom live more 
than a month. 
It should seem, that the more difficult suc- 
cess of this last kind of worm, after cutting, 
and the long time it takes to recover the lost 
parts, if it does recover them at all, are owing 
to its thickness; since we always find in that 
species of worms which succeeds best of all, 
that those which are thinnest recover their 
parts much sooner than the others. 
The water-insects also are not the only 
creatures which have this power of recover- 
ing the lost parts. The earth affords us some 
already discovered to grow in this manner 
from their cuttings, and these not less de- 
serving our admiration than those of the wa- 
ter: the common earth-worms are of this 
kind. Some of these wor ns have been dfe 
vided into two, others into three or four, 
pieces ; and some of these pieces, after hav- 
ing passed two or three months without any 
appearance of life or motion, have then be- 
gun to reproduce a head or tail, or both. 
The reproduction of the anus,, after such a 
state of rest, is no long work; a few days do 
it; but it is otherwise with the head, that 
does not seem to perform its functions in th# 
divided pieces till about seven months after 
the separation. It is to be observed, that in 
all these operations, both on earth and water- 
worms, the hinder part suffers greatly more 
than the fore part in the cutting; for it al- 
ways twists itself about a long time, as if ac- 
tuated by strong convulsions; whereas the 
head usually crawls away without the appear- 
ance of any great uneasiness. 
The reproduction of several parts of lob- 
sters, crabs, &c. makes also one of the great 
curiosities in natural history. That, in lieu 
of an organical part of an animal broken off, 
another shall rise perfectly like it, may seeia 
inconsistent with the modern system of gene- 
ration, where the animal is supposed to be 
wholly formed in the egg. Yet has the 
matter of fact been well attested by the fisher- 
men, and even by several virtuosoes whq 
have taken the point into examination, pair ■ 
ticularly M.'de Reaumur and M. Perrault,. 
whose skill and exactness in things of this,! 
nature will hardly be questioned. The legs, 
of lobsters, &c. consist each of five articula*/ 
tions: now, when any legs happen to break 
by any accident, as in walking, &c. which 
frequently happens, the fracture is always, 
found to be in a part near the fourth articu- 
lation ; and what they thus lose is precisely 
reproduced some time afterwards ; that is, a 
part of a leg shoots out, consisting of four 
articulations, the first of which has two claws 
as before, so that the loss is entirely repaired. 
If a lobster’s leg is broken off by design at 
the fourth or fifth articulation, what is thus 
broken off always comes again; but it is not 
so if the fracture is made in the first, second, 
or third articulation. In those cases, the re- 
11 
