Evening star., 1899-04-08
Reasons for Believing That 1t is
Growing Longer.
COMPARISON OF YOUTH And old AGE
What Modern Conditions Have
Done for the Human Race.
BIRTHS AND NJ RRIAGE S

DR. w AiuSlie Hollis IN Inc independent
Every man desires TO live long, but no
man would be DID," wrote Jonathan swift
about a couple of centuries ago, and the
sentiment is as popular now on both SIDES
of the Atlantic as it was then Whether the
wish in this case has been father 10 more
than the thought. ana parental yearning
had subsequently induced in the children
such bodily modification as is requisite to
IenEthen the duration of their youthfulness,
or whatever the cause may have been, L
shall show in the following paper that We
do live not only longer lives than our Tor
bears did but also younger lives as We'll
and Furthermore that these changes in the
social details of mans life are apparent
ly progressive.
The relation of the length of youthfulness,
which ceases with growth, to length OF NE
varies greatly in different animals. Flour
ems in his work on human longevity, makes
the ratio of length of growth TO length OF
life in a mammal, L TO - BuIIon ndu
previously estimated IT as L 10 - III heluiei
case were the data whence these coTclu-
Si0ns were drawn sufficiently numerous VI
1r1tstyy worthy to make them generally ac-
ceptabie. Through the kindness OF seVeral
CORRESPONDENTS, interested in the breeding
and rearing of various kinds of domeSuc
mammals, l am enabled to publish IN the
pages of the Independent some ne" anu
important facts bearing upon TINS SUBJECT.
Among domestic mammals the rule seems
10 be that the shortest lived species pass
the smallest fraction of their lifetime in
growth and development, IN otner "ofus,
I'm adolescence For instance, the donlestlc
mouse, which is fully matured about three
months after birth, may be expected 10
live fifteen times that period as an ADULT
Man. on the other hand, whose growth is
not usually completed until the twenty
fifth year by the union of the eplphysis Oh
the collar bone to its shaft, can only nope
TO live about twice that period as an adull
even under favorable conditions.
There is no doubt that the length of ado
leScenCe also varies in different breeds OF
the same species; and as a rule those breeds
which have the longest duration of youth
fuln.Ss are also the lOugest-liYed varieties
Highland and Welsh cattle, mountain
Scotch and mountain Welsh sheep, Arab
horses and Angora rabbits are all of them
slowly growing breeds. and they are appar-
entity long-lived varieties By arunclal Sc
lection man has shortened tne duoitScehce
of some breeds, such as HerefordS ana
Shortnurns. among cattle; Oxf0rds ana
HampShirtS among SnGep, MiddleWhlte pigs,
Dutch and Polish rabbits. As these ami
mails form an important portion OF our food
supply. stock keepers ind II 10 thelr inter-
est 10 rear those kinds which quickly be-
cont. ready for the market and my IN
f1rrnants are generally of opinion that
these breeds are the shortest-hNed we
Nay therefore conclude that as REGARDS 40
nestle animals the duration OF youlhtulneSS
is largely dependent on artlnclal selecIloIi'
and that yure-bIOOded varieties Of the same
sock may differ greatly in this respect
from each other Moreover there Is pre-
sumptive evidence. founded on the expert
,-uce Of the breeders and rearers OF Such
stock that the shOrtest-lived breeds are
those which complete their growth most
quickly.
Mans Exceptional Position.
The. position which man occupies in the
animal world is an exceptional one. 1t Is
2 legitimate subject of inquiry whether or
no the same law applies to him There Is
no doubt that the older anatomists have re-
corded cases where the osseous union of the
epiphyses 10 their respective long bones has
been found by actual dissection to have
been greatly delayed one OF the most note
worthy Is that OF man aged tWenty-SeVei
years in whose skeleton Otto observed an
The epiphyses 10 he separate (South
Pathological Anatomy page 126) -,
A skt .t.ou 50 completely osslfed could
not have finished its growth for another
len or twelve years. had the man lived ne
might truthfuIly have posed as youth
when ne was the verge Of forty: let
Notwithstanding this and other well-knoWn
Instances Of rriar,ir,! growth. the true sig
ulfi.anct Of the I-ust ulES OF the adoleS-
cent period disclosed in this manner was
apparently overlooked: and We stiH f1nd
that just as the law of Great Britain h1es
the limit Jf legal infancy az the age OF
twtnty-Oa=- 50 our medical puHdits nave
assigned the age Of twenty-five years as
th- date Of the completion OF growth by the
union Of tae last remaining epiphyses of
the shoulder girdle 10 their long bones. This
cate j. only an approximate one. Thanks
TO Prof koHtgen. We can. IL necessary,
watch Inc progressive changes In a growing
bone day By day. and can record them BY
such means / have found a difference OF
upward Of three years in the age at which
O<seuus union Is effected in a similar bone.
The SEIaErdInS recently published by Mr..
john Poland i'll his work on "TTaumatic
Separation Of the Epiphyses' confirm this
observation by other Instances OF ike pur-
II therefore. accepted true
that human skeiecai growth Is variable in
duration. AID, moreover, variability is
even observable III the growth of individ-
uaiS Of the same race
Backward Children.
IncomrIeteness OF bony growth implies
corresponding incOmpleieness in the growth
of the soft structures surrounding or closely
Connected with their oSseous supports.
Slpwiy maturing children are usually back
ward IN Intelligence. Their brains are less
receptive than the average childs brain of
. 1hc same age Any system of primary edu-
cation founded upon series of fixed age
standards. our English system for the
most part l.. may seriously imperiI child )
health and may permanently injure his
Dram by oNertdAlnS II TOO early IN lie.
Many promising scholar has been doubt
less spoiled by this system. An expert can
now readily ascertain by skiagrams
whether the CkW,ITduesS of child is due
10 laZiGess 70 uHJuiy retarded growth
that II al cases Of doubt recourse 10 his
Gii-IIoU ought To LIE made obligatory
teachers and others concerned with the
care OF the young
Proportion is Increasing.
Hitherto attention has been drawn to the
fact that We have percentage of slowly
developing young people among US; l shall
now show by taking the figures published
by the registrar general of births. deaths
and marriages III England and Wales that
80 far, at ali events, as these countries are
concerned, the proportion of slowly develop
ing ddo!escents 10 the whole population is
progressively increasing. In the fifty-ninth
annual report there are series of tables
dealing with the marriage age. We can as
certain from them that the mean unarria pe
age OF spinSters under forty has risen from
2l-S years In 1915 to 2.i.S years in 1896 The
average marriage age Of bachelors showed
meanN lille during the same period evil
denceS OF u SJl4I more remarkable Increase
However. il is with the spinsters that / am
mostly concerned in the present instance
NO satisfactory explanation until now has
been offered of this tendency Of children
10 defer their marriage 10 later age than
was customary with their parents For we