Year: 1867

AGASSE.


Prof. LOUIS AGAssIz delivered the fifth lecture of
his before the Society for the Advancement of Sci
and Art Cooper Institute last night His theme
the " Land Animals of South America. He said:


LADIES AND GENTLEMEN This is not the place for a
euogy, and yet cannot begin this lecture without say
ing few words Of that man to whom the City Of New
York has rendered the last honors today-Prof Alex
ander Dallas Bache the Superintendent OF the Coast
Survey He was Of those men whom all loved who
knew him. hut while he dear TO his friends he


man of whom his country well be proud He has
ganzed these United States erected upon ele
mehtary organization which had been laid out before
him. work which has made science, as represented and
carried in America, respected wherever science is cu
tvaed The Coast Survey Of the United States the
perfect survey that has been carried any
where and this is the work of Bache in this perfection
Bache had the talent OF bringing to his work
the most advanced results Of science and to apply them
10 practical purposes and again to make his work con-
tribute the progress of science in manner which has
advanced geology in America far beyond which it is any
where else fAppause And then he had another merit.
rendered science respectable in the councils Of
nation and hereafter science cannot be shut out from
the service of the country and from the great undertake
ings which have national character This much felt
should be allowed say here, while diScoursiDg upon
scientific subjects In honor ana memory OF one VINO was
80 dear 60 me Applause Ihe subject OF ms lecture G
what stated in my last lecture, you have already per
ceved that between the fresh water and terrestrial ami
mails there hardly be distinct line of domarka-
ton: In the aquatic and terrestrial animals,
enOther SO far their structure is concerned;
There is haEGy large group OF tne me amman amman
trial representatives and the anities between these in
habants OF different parts OF our globe are sometimes
very close. But there are relations among them which
deserve especial attention and that may the better
bring out these relations permit me 70 show you In what
relative position the classes of yerteea stand to one an
other that may demonstrate how these ideas Of grad
nal transition from one type to another have entered the
mind OF man and been supported with arguments appa-
renty unanswerabe The type of vertebra embraces at


least four classes, and classes TO be distinguished
one from the other by the various modes accOruhg 10
which given plan OF structure IS carried out we may
perhaps divide the verebras into still larger number OF
classes but those which are now universally rec0gnNeu
will suffice for my purpose The fishes are the lowest
est mamnalia at the head of which stands man
Now it is not conceit alone which justifes the
every evidence which can be adduced from an exana
ton OF mans structure, of mans anatomy. OF the power
of his faculties OF the constitution of his brain of the
st0n Of his body he deserves that position When we
study his relation TO the other living beings and when we
examine their order of succession in course OF time from
the earliest geological periods to the present day IT un
miStakabe that from the beginning the coming OF is
announced in the animal kingdom, and that his appear
the close of plan which initiated when the
relation types which have
habed the surface Of tho globe from the earliest period
TO the present day. few words concerning the
differences OF the structure will satisfy you hope
that such position is the true position which we
shOuid assign 10 he different classes ana the true posi-
ton which man has right 10 claim in the plan OF crea-
ton In the first place the class of fishes embraces only
aquatic aurnalSanimals in which the different regions
of the body hardly marked out The head the neck



mbroken continuous line. There is that articu
lation OF the whole figure which distinguishes regious
parts other parts For instance in
man. the head above al the other parts, and IN such
commanding position that it is plain to any one who
compares with the other beings living on this
his head the position Of his head the prominence Of the
forehead the size of the bran the relations OF the limbs
60 the trunk the vertical attitude which requires only
one pair OF limbs for ocOmotion while
sulervicnt tools for all the Of the mind all that
shows that man stands uppermost in the animal creation
while in the other classes the limbs entirely in the
service OF OcOmoOn and no longer at the service Of the
tcnce When TO the class Of fishes these very
different divisions are all uniform, and can hardly he
moved one separately from the other In fact the at


ude of the fish in the element in which il lives shows its
low position The fsh moves hOriz0ntaly ana the mead
Is level with ell the other parts Of the body Drew
charictersc Of the lowest type Of verebraes There
is no part which has such g preponderance over the
is the in the other vertebrates. How slight


change need TO make here in order 10 give TO this
animal entirely different expression, you will readily
sec In the first place. the caudal appendage may be
sionsaoh Of the ckbone. We have here at once the
characteristic form Of the tail Of all reptiles and all ami
mals thai have cauda appendage In the same manner
%e may exinguish these fapPers which are only folds
and assign to the head preponderance over the rest Of
you that its whole relation is changed, and
then have the FIRST aspiration in the animal kingdom
fins the limbs into which they are transformed; and thus
we gradually pass through the dieIent tanSiorihaGs
instead OF vertebrate provided with fins q vertebrate
provided with legsa reptile And if the gllls, which are
the progress Of growth and lungs are uolded thel we
series step higher; we have reached the class
reptiles the reptiles have STILL cold blood
and simple crculaton as We noticed among The fishes
one step further viii be gained If the circulation be
complicated and the means OF respiration be more eNel
sive; because In consequence Of the greater lnten
sty Of breathing the blood grows warmer. An |
other change Il that the distinction betWeeh |
the head and body may be better marked |
From tue lowest class OF the vertcbrates the body OF
which moves horizontally IN their natural ma element Meh
ascend the class OF reptiles in which the respiratory
plicrc air and forming the lowest Kind Of lungs The
Tins which first the side Of the body near the mead
und about midway back between the tan and the hedd
become feet with distinct fingers ana ne BODY may IA
be raised above the ground. II may leave the
organs serving as fms sim even thOugh Ley nave the
form Of fingers, the fingers being WcDbtd, ana so on
Another step beyond hat, We Ise 10 1e GiaS & ot
buds. Here the circulation OF the bOod is double
Is. part Of the blood arising nom me healt goes
immediately to the body ana laniilcs III an Hs |
parts "hlie another pant goes 10 tne iteSPile9loS
organs and is brought in contact with atmOs-
phcrc arr 80 that there is an extensive oI
the blood u that contact Wlcl stimulates u ICf ts Iuc
tOns aud in consequence OF that activity Ot he cfcua
tiOn and OF the intensity OF the breathing me tenpeIa
ture OF the body is raised above that OF e Surrounding
medium aud maintained in an Independent ,Tela- |
tion from that Of the surrounding medium |
The lower animals-repules ana hsles-aie caled
cOld-blOOded animals Not that the temperature is !
necessarily much colder than that OF the armDOoded
animals but II changes with the temperature of the sur
rounding medium. The turtle, in midsummer when eX-
posed the will have its temperature raised 10
own tcmperature-that OF its blood-w fan TO 90 to %
even; aud II sinks below then dies. But this animal
is not by IL organizations capable OF maintang MS temper
ature a fixed standard while this Is character Of the
wIrn-bOOded animals. NOu see here higher grade OF
orgauilatiop-a higher standard OF the function
and that becomes Characteristic of the birds But birds
have features in common win Itpte5 lht4 lay
cccs and in these eggs the Young are developed without
close connection with the parent and in many other
birds and reptiles is so close that at some
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