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

law of correlated variation. 1t should follow |
that when one part L. modified through long
selection, either by man or under |
nature other parts OF the organization will be |
unavoidably altered and It Is Il fact that with |
our domesticated plants and animals, varieties
rarely or differ 10y single character alone.
II the beak Of birds, for instance, increases or
decreases I'm length, adjoining or correlated
parts, rs the tongue and the ornce Of the nos
trils, tend to vary in the same manner. Homol-
cgous purts which are Identical in the embryo.
and ere exposed to similar conditions, deviate
In the same or In some connected way. as with
the tisnt and left sides OF the body. OF with tho
front and hind limbs. The skin and the APPEND
ages " hair, feathers, hoofs horns and teeth are
homologous over the whole body. Accordingly
tcvcral tropical breeds Of sheep. which are
clothed with hair instead OF wool. have horns
very like those OF Il goat. with men, striking
instances have been recorded Of inherited bald
ness, coupled with hereditary deficiency, either
complete or partial, OF the teeth. Darwin cites
tho case OF a Hindoo family, Of which ten males
In the course Of four generations were furnished
in both jaws taken together, with only four
weak Inclsors and eight molars the same men
had very little hair on the body and Became
bald early in life. alt Ia remarkable" he adds,
"that no instance has occurred In that fam
fact reminds us how much more liable men arc
in ENGLAND to become bald than women" In
this category belongs the case Of Julia Pastrana,
a Spanish dancer, who had thick masculine
beard and hairy forehead, and, correlated with
these pccullarities, a fun double set Of teeth In
each jaw, one row being placed within the
other 1t seems further to be admitted that the
organs II sight and hearing are homologous
with one another Thus color-blindness Is often
associated with n corresponding Inability to dis-
tueuish musical sounds. White cats. 10 they
have blue eyes, are almost always deaf. Here
the cause is supposed to lie in slight arrest Of
development in the nervous system connected
with the sensc-organs a. the stage Of the closed
eyclids, as the iris In kittens during that pc
Rod has been found to be 81 a blue color. Final
". there s some authority for the old belief that
In man las certainly In animals) there is a con-
necton between complexion and constitution.
II has been shown, for Instance, that relation
exists between liability to consumption and the
color Of the eyes, hair, and skin. 1t IL even at
hrned that In the French army which invaded
Russia soldiers having dark complexion, from
the southern parts Of Europe, wthstood the in
tense cold better than those with lighter COM
plexiors from the north. A TO piga and sheep,
there Is no doubt that the white sorts are poi
soned by various plants which prove nnocuous
W
Of the action ofiany pois cases have been pub
lished Of cutaneous diseases affecting every
single point which bore a white hair but COM
pletely passing over other parts Of the body.
White terriers suffer most from the distemper,
and white chickens from the gapss. Analogous
facts have been observed with plants white
onions and verbenas are the most liable to mill
dew, and in Spain the pale fruitcd grapes suffer
most from the VINO disease. He'd whedts Ike
wise 're na'u'er 'n"n "h''e' All 'his wound IN
u'o"'e '"a' some grave constitutional uInerehee
mus nc correla'ed win Color
inc uocttihe OF the amnity OF homologous
pHts pronounced bN Ieonrog Saint-H'lalre,
substantially afhrmed that these actually attract
""e "ho'nei anu theh unite lhere are DOUBT
less cases IN which such parts become inti-
"a'vN iuseu tose'her' and this Is seen In mon
s'ers win TWO hehus "hlch are united summit
10 sun III i1ce 10 race or Janus-like' back TO
PACK but IN all these instances 1t Is now
thousht oy the greater number OF competent
JUICES mat the homolo-ous parts are not mu-
tuplP attractive out that as union taxes place
pci'ro .uo u'"e'e"'i'''o" oi u,st'no' organs
occurs 'nese 're nc'ef 'V''peu W continuity
VII" ecu o'"vr. !" appears 10 ioHow mat
vs. ''s "'''"H' u'"e'e"''a'eu ""uu J." no c'se
'e0''V N'''''N " "o"O''@0us ""es' pS ""a'
ever MEANS however tue aohotmai fusion OF
"Ns us i ""e''eu' SUI" eNa"PIes 'nro" "sht
." 'ne iIel"e"' presence oi organs wn'ch are
u'u"F u"''ns 'hc emt rEVh'c perlou lana 80 re-
man throughout mo IN lower members 81 the
same cl1ssl' tut which aiterward unite into a
single medial organ.
IL WouId seem that multiple ana homologous
orSaus are especially liable To vary in mum er,
ana probably IA form. As the supply OF organ
ized matter Is rot unlimited the principle OF
compensation sometimes comes into action
So that when one part Is greatly developed adj
/ lhlhg parts are likely 10 be reduced; but this
! prnclple Is believed 10 be OF much less Import
ance than the more general one OF economy of
/ growth Again. through mere mechanical pres
sure hard parts OCCASIONALLY Affect parts ad
| Jiceut. win plants, moreover, the position OF
flowers on the axis aud OF the seeds in the
ovarS sometimes leads through a more or les:
| How ol sap TO changes OF structure. Modilca-
| uohs' IN Whatever manner caused, VIII be, to q
certain extent controlled by that coordlnating
lower formerly stVlcd the nlsle' l"m NitUs
Whlch Is IN lack a remnant OF thar simple iorl
OF reproduction displayed by many lowl. or
ehi@ed LelhRs IN thelr power OF h'sipArou'
generation and budding Finally the elects o
the Laws which directly or indirectly govern
| variability may ne largely regulated by mani