Daily Kennebec journal. [microfilm reel] (Augusta, Me.) 1870-1975, 1872-01-11

,a,or Obtained that these embryos were,
fshes: suffice IL to say that the dorsai cor"
Win lis heteroceral bent was readily .lsi-
Ne as well as the caudal fin with Its rays
/, the eyes the colobome had not yet oeeh
fnlly closed, and blood currents were un-
mistakable upon the yoik bags. bu',
What kind of fish was this About tne
time of Matching, the fms OF tins class Oh
animals differ too much from those OF the
adult, and the general form eXhiolts 700
few pecularities to afford any clue TO TINS
problem, could only suppose that It
would probably prove to be one I'll the
peiagie species of the Atlantic. and of
these the most common are eXocoetus,
naucrates, scopelus, chronicles, syngne-
thus. monacanthus, tetraodon. and diodon.
Was there a way to come nearer to a So
luton of my doubts
As I had in former years made a some |
what extensive study of the pigment cells
of the skin, in variety of young fishes,
now resorted to this method to identify
my embryos. Happily we had on board
several pelagie fishes alive, which could
afford means of comparison, but unfortu-
nately the steamer was shaking too much
and rolling too heavily for microscopic
observation Of even moderately high pow
ers. Nothing, however, should be left
untried and the very first comparison
made secured the desired result. The pig
ment cells of a young chronicles pictus
proved identical with our little embryos.
1t thus stands as well authenticated fact
that the common pelagic chronicles Of
the Atlantic (named chronicles pictus by
Cuvier,) build nest Tor its eggs in which
the progeny in wrapped up with the ma
terials of which the nest itself is compos-
ed and as these materials are living Gulf
weeds, the fish-cradle. rocking upon the
deep ocean, is carried along as an indy
ing arbor, affordng at the same time pro-
lection and afterward food for its living
freight.
This marvellous story acquires additional
interest if we now take into consideration
what are the characteristic peculiarities
OF the chronicles. AS its name indicates,
il has fins like hands; that is to say. the
pectoral fins are supported by a kind Of
prolonged, wristlike appendages, and the
rays vi the ventrals are not unlike rude
fingers. With these limbs these fishes
have long been known to attach them
selves to seaweed, and rather to walk
than to swim in their natural element.
But now that we have become acquainted
with their mode of reproduction, it may
fairly be asked is. the most important use
to which their peculiarly constructed fins
are put is not probably in building their
nest. The discovery OF this nest was
quite accidental, but not so the examina-
ton OF the large masses of the floating
weeds which We met with as soon as we
entered the water of the Gulf Stream
had made it my chief business to examine
the floating safgassum, with the intention
OF solving if possible the question of its
origin. / had delivered lecture to ali
on board, in which was stated all know
upon the subject, and what | wanted to
ascertain further; thus hoping to enlist
the interest of the officers of the ship and
of my scientific fellow-travelers in the OBJ
ject OF my search. had told them that l
did not believe that the Gulf weed could
multiply while floating. even though the
floating branches might enlarge had
suggested the gathering of the smallest
branches of the weed, with a view to as
certaining, whether not all. even the very
smallest, bore signs of having been torn
violently. away from fixed attachment.
From that day not a patch of Gulf weed
passed our ship within reach that was not
carefelly looked at and hauled up if it
presented any peculiar appearance, and
no doubt l have my reward for that lee
ture in the discovery of the nest of chiron-
ectes. There remains one closing chapter
TO add to this story. May some natural
list becalmed among the Gulf weed have
the good fortune OF witnessing the process
by which the nest is built From an EN-.
theological point of view. these little fish
es are quite interesting. In the first place
the embryonal vertical fin, which extends
along the whole back in the fish embryos
thus far known. begins very far behind in
the young chronicles, and does not exist
upon the neck and back. In the second
place, the position of the heart is very
peculiar. Instead of lying at the junction
of the yolk-bag with the head, it occupies
a low position in the front part OF the
yolk.
All the officers of the Hassler are indie.
fatigable in their efforts to help our inves.
legations, and even the men show useful
interest in our proceedings. We have
just reached St. Thomas, SO that have
nothing to add as to observations made
here. Ever truly your friend.
l.. AGAssIZ.
To Prof. Benjamin Pierce, Supt IT, S
Coast Survey.