on the relations of man to the lower animals-第4部分

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column；　while　the　arm　is　not　more　than　11/18　of　its　length；　the　hand
having　rather　less　and　the　foot　rather　more；　than　one…third　the　length
of　the　spinal　column。

These　examples　might　be　greatly　multiplied；　but　they　suffice　to　show
that；　in　whatever　proportion　of　its　limbs　the　Gorilla　differs　from　Man；
the　other　Apes　depart　still　more　widely　from　the　Gorilla　and　that；
consequently；　such　differences　of　proportion　can　have　no　ordinal　value。

We　may　next　consider　the　differences　presented　by　the　trunk；　consisting
of　the　vertebral　column；　or　backbone；　and　the　ribs　and　pelvis；　or　bony
hip…basin；　which　are　connected　with　it；　in　Man　and　in　the　Gorilla
respectively。

In　Man；　in　consequence　partly　of　the　disposition　of　the　articular
surfaces　of　the　vertebrae；　and　largely　of　the　elastic　tension　of　some
of　the　fibrous　bands；　or　ligaments；　which　connect　these　vertebrae
together；　the　spinal　column；　as　a　whole；　has　an　elegant　S…like
curvature；　being　convex　forwards　in　the　neck；　concave　in　the　back；
convex　in　the　loins；　or　lumbar　region；　and　concave　again　in　the　sacral
region；　an　arrangement　which　gives　much　elasticity　to　the　whole
backbone；　and　diminishes　the　jar　communicated　to　the　spine；　and　through
it　to　the　head；　by　locomotion　in　the　erect　position。

Furthermore；　under　ordinary　circumstances；　Man　has　seven　vertebrae　in
his　neck；　which　are　called　'cervical'；　twelve　succeed　these；　bearing
ribs　and　forming　the　upper　part　of　the　back；　whence　they　are　termed
'dorsal'；　five　lie　in　the　loins；　bearing　no　distinct；　or　free；　ribs；　and
are　called　'lumbar'；　five；　united　together　into　a　great　bone；　excavated
in　front；　solidly　wedged　in　between　the　hip　bones；　to　form　the　back　of
the　pelvis；　and　known　by　the　name　of　the　'sacrum'；　succeed　these；　and
finally；　three　or　four　little　more　or　less　movable　bones；　so　small　as　to
be　insignificant；　constitute　the　'coccyx'　or　rudimentary　tail。

In　the　Gorilla；　the　vertebral　column　is　similarly　divided　into　cervical；
dorsal；　lumbar；　sacral；　and　coccygeal　vertebrae；　and　the　total　number
of　cervical　and　dorsal　vertebrae；　taken　together；　is　the　same　as　in
Man；　but　the　development　of　a　pair　of　ribs　to　the　first　lumbar　vertebra；
which　is　an　exceptional　occurrence　in　Man；　is　the　rule　in　the　Gorilla；
and　hence；　as　lumbar　are　distinguished　from　dorsal　vertebrae　only　by
the　presence　or　absence　of　free　ribs；　the　seventeen　〃dorso…lumbar〃
vertebrae　of　the　Gorilla　are　divided　into　thirteen　dorsal　and　four
lumbar；　while　in　Man　they　are　twelve　dorsal　and　five　lumbar。

FIG。　15。Front　and　side　views　of　the　bony　pelvis　of　Man；　the　Gorilla
and　Gibbon：　　reduced　from　drawings　made　from　nature；　of　the　same
absolute　length；　by　Mr。　Waterhouse　Hawkins。

Not　only；　however；　does　Man　occasionally　possess　thirteen　pair　of　ribs；*
but　the　Gorilla　sometimes　has　fourteen　pairs；　while　an　Orang…Utan
skeleton　in　the　Museum　of　the　Royal　College　of　Surgeons　has　twelve
dorsal　and　five　lumbar　vertebrae；　as　in　Man。　　Cuvier　notes　the　same
number　in　a　'Hylobates'。　　On　the　other　hand；　among　the　lower　Apes；　many
possess　twelve　dorsal　and　six　or　seven　lumbar　vertebrae；　the
Douroucouli　has　fourteen　dorsal　and　eight　lumbar；　and　a　Lemur　（'Stenops
tardigradus'）　has　fifteen　dorsal　and　nine　lumbar　vertebrae。

　　　　＇Footnote＇*　〃More　than　once；〃　says　Peter　Camper；　〃have　I　met
　　　　with　more　than　six　lumbar　vertebrae　in　man。。。。　　Once　I
　　　　found　thirteen　ribs　and　four　lumbar　vertebrae。〃　　Fallopius
　　　　noted　thirteen　pair　of　ribs　and　only　four　lumbar　vertebrae；
　　　　and　Eustachius　once　found　eleven　dorsal　vertebrae　and　six
　　　　lumbar　vertebrae。'Oeuvres　de　Pierre　Camper'；　T。　1；　p。
　　　　42。　　As　Tyson　states；　his　'Pygmie'　had　thirteen　pair　of　ribs
　　　　and　five　lumbar　vertebrae。　　The　question　of　the　curves　of
　　　　the　spinal　column　in　the　Apes　requires　further
　　　　investigation。

The　vertebral　column　of　the　Gorilla；　as　a　whole；　differs　from　that　of
Man　in　the　less　marked　character　of　its　curves；　especially　in　the
slighter　convexity　of　the　lumbar　region。　　Nevertheless；　the　curves　are
present；　and　are　quite　obvious　in　young　skeletons　of　the　Gorilla　and
Chimpanzee　which　have　been　prepared　without　removal　of　the　ligaments。
In　young　Orangs　similarly　preserved；　on　the　other　hand；　the　spinal
column　is　either　straight；　or　even　concave　forwards；　throughout　the
lumbar　region。

Whether　we　take　these　characters　then；　or　such　minor　ones　as　those　which
are　derivable　from　the　proportional　length　of　the　spines　of　the
cervical　vertebrae；　and　the　like；　there　is　no　doubt　whatsoever　as　to
the　marked　difference　between　Man　and　the　Gorilla；　but　there　is　as
little；　that　equally　marked　differences；　of　the　very　same　order；　obtain
between　the　Gorilla　and　the　lower　Apes。

The　Pelvis；　or　bony　girdle　of　the　hips；　of　Man　is　a　strikingly　human
part　of　his　organization；　the　expanded　haunch　bones　affording　support
for　his　viscera　during　his　habitually　erect　posture；　and　giving　space
for　the　attachment　of　the　great　muscles　which　enable　him　to　assume　and
to　preserve　that　attitude。　　In　these　respects　the　pelvis　of　the　Gorilla
differs　very　considerably　from　his　（Fig。　15）。　　But　go　no　lower　than　the
Gibbon；　and　see　how　vastly　more　he　differs　from　the　Gorilla　than　the
latter　does　from　Man；　even　in　this　structure。　　Look　at　the　flat；　narrow
haunch　bonesthe　long　and　narrow　passagethe　coarse；　outwardly　curved；
ischiatic　prominences　on　which　the　Gibbon　habitually　rests；　and　which
are　coated　by　the　so…called　〃callosities；〃　dense　patches　of　skin；
wholly　absent　in　the　Gorilla；　in　the　Chimpanzee；　and　in　the　Orang；　as
in　Man！

In　the　lower　Monkeys　and　in　the　Lemurs　the　difference　becomes　more
striking　still；　the　pelvis　acquiring　an　altogether　quadrupedal
character。

But　now　let　us　turn　to　a　nobler　and　more　characteristic　organthat　by
which　the　human　frame　seems　to　be；　and　indeed　is；　so　strongly
distinguished　from　all　others；I　mean　the　skull。　　The　differences
between　a　Gorilla's　skull　and　a　Man's　are　truly　immense　（Fig。　16）。　　In
the　former；　the　face；　formed　largely　by　the　massive　jaw…bones；
predominates　over　the　brain　case；　or　cranium　proper：　in　the　latter；　the
proportions　of　the　two　are　reversed。　　In　the　Man；　the　occipital
foramen；　through　which　passes　the　great　nervous　cord　connecting　the
brain　with　the　nerves　of　the　body；　is　placed　just　behind　the　centre　of
the　base　of　the　skull；　which　thus　becomes　evenly　balanced　in　the　erect
posture；　in　the　Gorilla；　it　lies　in　the　posterior　third　of　that　base。
In　the　Man；　the　surface　of　the　skull　is　comparatively　smooth；　and　the
supraciliary　ridges　or　brow　prominences　usually　project　but
littlewhile；　in　the　Gorilla；　vast　crests　are　developed　upon　the
skull；　and　the　brow　ridges　overhang；　the　cavernous　orbits；　like　great
penthouses。

Sections　of　the　skulls；　however；　show　that　some　of　the　apparent　defects
of　the　Gorilla's　cranium　arise；　in　fact；　not　so　much　from　deficiency　of
brain　case　as　from　excessive　development　of　the　parts　of　the　face。　　The
cranial　cavity　is　not　ill…shaped；　and　the　forehead　is　not　truly
flattened　or　very　retreating；　its　really　well…formed　curve　being　simply
disguised　by　the　mass　of　bone　which　is　built　up　against　it　（Fig。　16）。

But　the　roofs　of　the　orbits　rise　more　obliquely　into　the　cranial　cavity；
thus　diminishing　the　space　for　the　lower　part　of　the　anterior　lobes　of
the　brain；　and　the　absolute　capacity　of　the　cranium　is　far　less　than
that　of　Man。　　So　far　as　I　am　aware；　no　human　cranium　belonging　to　an
adult　man　has　yet　been　observed　with　a　less　cubical　capacity　than　62
cubic　inches；　the　smallest　cranium　observed　in　any　race　of　men　by
Morton；　measuring　63　cubic　inches；　while；　on　the　other　hand；　the　most
capacious　Gorilla　skull　yet　measured　has　a　content　of　not　more　than
34…1/2　cubic　inches。　　Let　us　assume；　for　simplicity's　sake；　that　the
lowest　Man's　skull　has　twice　the　capacity　of　that　of　the　highest
Gorilla。*

　　　　＇Footnote＇　*It　has　been　affirmed　that　Hindoo　crania
　　　　sometimes　contain　as　little　as　27　ounces　of　water；　which
　　　　would　give　a　capacity　of　about　46cubic　inches。　　The　minimum
　　　　capacity　which　I　have　assumed　above；　however；　is　based　upon
　　　　the　valuable　tables　published　by　Professor　R。　　Wagner　in
　　　　his　〃Vorstudien　zu　einer　wissenschaftlichen　Morphologie　und
　　　　Physiologie　des　menschlichen　Gehirns。〃　　As　the　result　of　the
　　　　careful　weighing　of　more　than　900　human　brains；　Professor
　　　　Wagner　states　that　one…half　weighed　between　1200　and　1400
　　　　grammes；　and　that　about　two…ninths；　consisting　for　the　most
　　　　part　of　male　brains；　exceed　1400　grammes。　　The　lightest
　　　　brain　of　an　adult　male；　with　sound　mental　faculties；
　　　　recorded　by　Wagner；　weighed　1020　grammes。　　As　a　gramme
　　　　equals　15。4　grains；　and　a　cubic　inch　of　water　contains　252。4
　　　　grains；　this　is　equivalent　to　62　cubic　inches　of　water；　so
　　　　that　as　brain　is　heavier　than　water；　we　are　perfectly　safe
　　　　against　erring　on　the　side　of　diminution　in　taking　this　as
　　　　the　smallest　capacity　of　any　adult　male　human　brain。　　The
　　　　only　adult　male　brain；　weighing　as　little　as　970　grammes；
　　　　is　that　of　an　idiot；　but　the　brain　of　an　adult　woman；
　　　　against　the　soundness　of　whose　faculties　nothing　appears；
　　　　weighed　as　little　as　907　grammes　（55。3　cubic　inches　of
　　　　water）；　and　Reid　gives　an　adult　female　brain　of　still
　　　　smaller　capacity。　　The　heaviest　brain　（1872　grammes；　or
　　　　about　115　cubic　inches）　was；　however；　that　of　a　woman；　next
　　　　to　it　comes　the　brain　of　Cuvier　（1861　grammes）；　then　Byron
　　　　（1807　grammes）；　and　then　an　insane　person　（1783　grammes）。
　　　　The　lightest　adult　brain　recorded　（720　grammes）　was　that　of
　　　　an　idiotic　female。　　The　brains　of　five　children；　four　years
　　　　old；　weighed　between　1275　and　992　grammes。　　So　that　it　may
　　　　be　safely　said；　that　an　average　European　child　of　four
　　　　years　old　has　a　brain　twice　as　large　as　that　of　an　adult
　　　　Gorilla。

No　doubt；　this　is　a　very　striking　difference；　but　it　loses　much　of　its
apparent　systematic　value；　when　viewed　by　the　light　of　certain　other
equally　indubitable　facts　respecting　cranial　capacities。

The　first　of　these　is；　that　the　difference　in　the　volume　of　the　cranial
cavity　of　different　races　of　mankind　is　far　greater；　absolutely；　than
that　between　the