The sun. [volume] (New York [N.Y.]) 1833-1916, 1876-05-28
sOME NEW BOOKs.



scientists, the principle Of natural selection de-
yeloped by Darwin In his "Origin Of Species"
seem, to have made good its claim to general re-
coenition. II would nc absurd TO say that 1t has
attained place beside the law Of gravtation
among the universally approved deductions OF
science, vet its foothoid Is probably more secure
than that OF the ncbular hypothesis, or Of
the undllatory theory of Hight. The doc
trine of natural selection, however, pre-
supposed variability as the constant charao-
ter OF every organism. This postulate has been
vehemently impugncd. and the volumes before
us, The Variation Of Anfmrls and Plants undcr
Domesttcdtion (Appletons), may be said to form
pyramid VI convergug and cumulative arRu-
ment pointing to the CORE 'tness of the assump-
tion. The second edition OF the worn, which
now appears after lapsc OF some seven years,
has been buttrcssod with much additional ma
terial and the provisional hypothesis OF pm
genesis framed to co0riinltc and reduce beneath
one law all the phenomena Of diversity In
growth has been remOdellcd aud sigually eon-
forced.
The several sub-laws which govern variability
may be grouped under the effects OF use and
disuse, including changed habits and acclimn-
tizauon, arrested development, correlated vari-
alton, the cohesion OF homoogous parts, COM
pensation OF growth the abihtyto deviation OF
multiple parts, the position Of buds with re-
gous variability. These different subjects so
graduate into one another that their distinction
IL often arbitrary. but IL will DO convenient to
consider them briefly IN deiail before stating
the hypothesis watch aims to combine the d.
verse modes of Inherited mutability under a
general law.
1t Is notorious that Increased use or action
strengthens muscles, glands. sense organs, &C.,
and that dlsusc weakens them. 1t has been ex-
perimentally proved that the now OF blood Is
greatly augmented toward any part which is
performing work, and sinks again when the part
Is at res. Consequently II the exercise Is fire.
quent, the vessels expand and the part is better
nourished. When Hunter inserted, for instance,
the spur OF "A cock Into the comb, which Is well
supplied with blood vessels, It grew in one
case spirally TO a length Of six inches, and
In another case forward like a horn, so that
the bird could not touch the ground with lite
beak The rocking OF the stem OF tree Ia
creases In a marked manner the growth Of tho
woody tissue In the parts which are str lined.
Every one knows that hard work thickens the
epidermis on the hands, and when we hear that
with infants long before birth the skin h thicker
on the palms and soles, are naturally led to
attribute this to the inherited effects OF long.
continued use or pressure. with respect to cat
tie, II Ia remarked that the lungs and liver In the
improved breeds, which take little exercise and
are supplied with nutritious and artificial food.
ARE considerably reduced In size when CON .
pared with those possessed by animals having
perfect liberty" Again, our domestcated
quadrupeds are all descended from species
with erect ears, yet few kinds can be named OF
which, at least, one breed has not the ears
dropping. with wild animals, which constantly
nse this organ like funnel TO catch every pass
ing sound and especially to ascertain the direc-
lion whence 1t comes, no race has pendant ears
except the elephant. Hence the incapacity OF
erecting the ear Is plainly the result OF dOmes,l-
cation. and has been reasonably ascrbed by
various authors to the fact that creatures pro-
tected by man are not compelled habitually to
use this organ. Col Hamilton Sui.tA states that
in ancient Ell. es Of the dog, with the excep-
tion Of one Egyptian instance. 10 sculpture Of.
the earlier Grecian era produces representations
of hounds with completely dropping ears those
with them half pendulous are missing Ia the
most ancient, but tho pend mt character in
creases by degrees in the works Of the Roman
period"
1t is not easy TO determine how far the mod H.
cations induced by changed and inherited hab-
its Of life are due to mere custom, and how far
10 the selection OF Individuals which have
varied ia desired manner. sporting dogs, for
example, will not touch tho bones Of game
birds, whereas most other dogs deyour them
with greediness; bit this Il distinction which
breeders would seek TO emphasize. The domes-
tic hog Is fond OF barley, the wild boar IL said to
disdain II, and this disdan would seem TO be
inherited, for some wild pigs bred In captivity
"showed an aversion Tor this grain while others
OF the same litter relished IT," The period of
CESSATION aud maturity well the sea-
son and the act OF breeding strongly
affected by domestca.ion. Thus the wild
drake pairs with one female, but his domestic
fir T. r.,lt "a hat
certain eds Of fowls have lost the habit Of
iucubation. With plants, too, the PERIOD Of yese
tatOu Is easily Chau.el. AMI the deviation Is 10
leritod as In the case of summer and white
wheat. Under new climate, annual plants oc
cAsioually become perennial, and some dccidg
Gus buses become evergreen in hot countries
il l. to be noted that such radical alterations IL
the phenomena Of life, whether due 10 habit, L
the direct action Of selection, or to so-callc'
Spontaneous variability, would be apt TO entail
notifications OF structure.
To tbs category telones the much dIspute
ant ject ofacrlimatizaton. by many natur4 Inst
the attempt to acclimatlzs either animals o
plants has teen pronounced chimerA Wit
plants gr)paglted FROM bud, at all events, ha5
ituation to novel climatic conditions rarely pro
duces ans effect. Thus the Jerusalem aIuchoAl
produced from tuber-, IL sAll to be as t.nder 81
England ,.s when lrst inrJdu ed, AMI this .p
pears to be the case with the potato, which
until recently, was seldom multiplied by seed
Darwin comedies that even with seedlings anI
with animals there vii, be little OF no acclinAti
zation unless the harder I'm iividutls are eithe
intentionally or uuclnsciously preserved
Hut as no single instance has been recorde
sither with animals or plants " II harder ind
Vduals having be n long and steadily selected
though such selection is admitted TO be indh
l,hsatle for the Improvement OF any othe
character, 1t Is not surprising that man has don
LILLE ia the aochmatiz alton OF domestlcate
animals and cultivated plants" IL may well b
however that under nature races and specie
being Obliged to SHIFT for themselves, would bi
come adapted to widely different climate
through spontaneous variation regulated Uy III
oUerau1n Of the survival OF the nttest.'
Mudihcations OF structure from orrosted d
Neo.ment amounting to ilnnstrositics, may I
passed over; but the rudimentaTy organs whic
even with SPECIES In sttie Of nature, are e.
Nemely common, claim some attention. Ii
aotced That such ORGANS are peculiarly liable
Variation, Tor being u-eess, they are not inf