New-York tribune., 1873-05-03
LIFE AT BIRTH.
,rvTu 1FCTURE BY PROF. AGASSIz.

pEfIuI,RITIES- DISTINCTIONS OF sen IN TIE
BEEHIVE
IFRoN An OCCASIONAL CORRESPONDENT OF THE TRIBUNEl
CAMBRIDGE, Mass, May 1.-The following
lecture was delivered byPro AGassiz before the Mu
seum Of Comparative Zoology, on the 18TH ult'
No sooner had microscopes begun to lit the Vah
which hides the mysteries OF reproduction than attempts
were made 70 adapt the knowledge thus acquired both
Il, aenac and practical purposes The fact once ascer
tanned that the contact OF sperm cells ana eggs
Nyould bring about the production OF new being 1t be-
came evident that eggs and sperm cells might be taken
from the living which they arise ana their contact
secured artidcialy Of the first naturasts TO
try this artificial Foundation beginning my experiments
with FISH, Nv object mainly to trace their growth
and TO study their embryoogy. Several species Of fish
are particularly adapted 10 such investigations; partly
because they lay their eggs in the Auumn at season.
that is. when equabe temperature can easily De
maintained for longer period than at other times OF
the year. and also because they undergo their develop
ment very slowly thus making it possible TO wach uay
by day their successive transformations These crouu
stances favor embryological research
ARTIFICIAL PROPAGATION OF FISH
In my very first attempt the kind succeeded COM
r,eelv raised little fishes of the salmon family,
specles OF ghtehsh CoTegonus), in large bowl ID my
study and was follow every phase OF their ue'e
opment These experiments have been since not ohly
repeated but applied almost every class OF the animal
kingdom Indeed the fact that embryology is now SO
rocular modes OF growth Of different families OF the
animal kingdom is increasing daily, is mainly due TO the
added facilities for bringing these investigations within
our control through artificial Foundation Almost all
AQUATIC animals susceptible OF being treated in that
way. They can be fecundated in confinement, and
brought 70 maturity under the OF the naturalist But
the subject has gained another kind Of importance 1t
has a practical value. You are not unaware that
our modern civilization rests in great degree
upon the possibility OF multiplying and vary
ing articles of food. Have you ever considered
how largely food in America is an introduction from
other countries All fruit trees, nearly all cur gar
den vegetables all but of our grains, all our fowls
indeed all our domesticated animals and cultivated
plants are imporatiOns from abroad. And as pOpula
ons increase, this question Of susenanee becomes more
and more vital Could not bring sufficient amount
Of sutenance into large cities IL would be Impossible
for men TO crowd together in common ceners Tor social
contact for commercial exchange, for intellectual cu
ture It may well be said that the ability which men
have acquired for raising and multiplying their Iood at
will has been the foundation Of our higher ciyzau0n
Every new branch Of this kind Of industry becomes
new lever in raising the standard Of mental and physical
health and wellbeng, and improving the condition OF
man. 1 look upon it as one of the great
blessings OF day that so many attempts are
made and with promise OF so much success
10 increase multiply and vary our food and improve It's
quality by artificial formulation. When the rst ned OF
wheat was sOwn soil, who could have foretold
counted acres grain, ready to feed the Old World as
we'll as the New, ever fOrestang famine in distant and
oyercrOwded populations Can we measure the bene-
fcent work done by the cultivation of wheat and corn
alone bringing together, binding them III closer
as well a more comprehensive associations stimulating
the charities Of ie enhancing its comforts and raising
the whole tone Of human civilization 2 Neither is 1t
possible to say now how much will be added TO the pros
perty of our Commonwealth our general welfare and
10 the exchange Of good gifts between nations, Oy
artificial production Of animal ie especially When we
consider useless surfaces OF water now
checking and inerrupting agriculture, but to be
transformed into fish farms, not less productive than
our cultivated land The art Of raising fish arlhcialy
Is no longer dream 1t may be done, Ii has already
been done successfully and proves 10 be very profitable
VALUABLE RESULTS OF NEUROLOGICAL STUDIES
From practical point Of view alone then, the study
OF embryoogy has its importance in all civilized com
munIties; the more so since fish. on which these
experiments have chiefly been made is as an article Of
food especially beneficial in repairing the loss entailed
upon our system by the activity Of the BRAIN
The attempts at raising fish and other aquatic animals
are still in their infancy aud yet the result be
counted by millions. Some Of these arufcaly raised
fish are brought 10 market in great numbers There are
large cities in Europe whose principal supply Of fish
derived from this method Of production. need not
aude to the other animals which may be multiplied in
that way Oysters crabs and Holsters may be thus re-
produced increased and in those regions where sea
urchins are among the articles Of daily diet the choicest
aud most valued kinds will no doubt be multiplied by
this artificial process. 1t is impossible now for any
large communities crowded in small spaces to exist
without the artificial production Of food Nowhere does
Nature provide food in sufficient abundance for their
needs.
Nothing is more striking in considering the organiza-
ton of the animal kingdom whole than the count
less shades Of difference in the relations Of parents to
the egg and to each other These are so varied that
except as a history Of the whole animal kingdom, II
would be impossible to give them in detail There are
hardly two species Of animals which, in that respect live
alike From the intimate relation characteristic or the
human family and upon which all civilization is based
down to the loose relations OF lower animals, between
which such ties only temporary and OF
the slightest aud most insignificant nature, there
are so many degrees and such diversity
that picture OF the whole would demand very full
course of lectures devoted that subject alone Upon
such an initiative connection and its greater or less
closeness depend all the deeper relations OF e LOOK
at the condition of mammals. The young Is carried IN
the mother up 10 the VIXEN it is either capable OF
shifting for itself or advanced that requires
the care OF the parents only for short time. I'm man
alone that period Of dependence is prolonged and no
doubt 70 the protrdcted infancy OF man. aud ms slow
growth We owe the teuderet relations The dearest Ties
which bind TO another Thus IN one OF the SIN
pest and most essential conditions the maintenance
OF our type generation after generation. we nave the
basis OF our and OF the development OF our best
faculties and dispositions.
MATERNAL CARES AMONG DIFFERENT ANIMALS.
Length Of CESSATION among animals varies III the most
extraordinary degree. In some 10 lasts only lew DAYS
or weeks, in others a. is WOtracted through muny
months These differences also involve conditions es-
senta 20 the maintenance OF species, and insist upon
the diversity OF these conditions absolutely necessary
for the maintenance Of different kinds Of animals with
their distinct characteristics. Passing from tue animals
Tor long tne ~ ,,,a,e, whom the mother does
oftrf-n HerK