Calmuck； after Von Baer。 One…third the natural size。
I have arrived at the conviction that no comparison of crania is worth
very much； that is not founded upon the establishment of a relatively
fixed base line； to which the measurements； in all cases； must be
referred。 Nor do I think it is a very difficult matter to decide what
that base line should be。 The parts of the skull； like those of the
rest of the animal framework； are developed in succession the base of
the skull is formed before its sides and roof； it is converted into
cartilage earlier and more completely than the sides and roof： and the
cartilaginous base ossifies； and becomes soldered into one piece long
before the roof。 I conceive then that the base of the skull may be
demonstrated developmentally to be its relatively fixed part； the roof
and sides being relatively moveable。
Fig。 27。Oblong and prognathous skull of a Negro； side and front views。
One…third of the natural size。
The same truth is exemplified by the study of the modifications which
the skull undergoes in ascending from the lower animals up to man。
FIG。 28。Longitudinal and vertical sections of the skulls of a Beaver
（'Castor Canadensis'）； a Lemur （'L。 Catia'）； and a Baboon
（'Cynocephalus Papio'）； 'a b'； the basicranial axis； 'b c'； the
occipital plane； 'i T'； the tentorial plane； 'a d'； the olfactory plane；
'f e'； the basifacial axis； 'c b a'； occipital angle； 'T i a'；
tentorial angle； 'd a b'； olfactory angle； 'e f b'； cranio…facial angle；
'g h'； extreme length of the cavity which lodges the cerebral
hemispheres or 'cerebral length。' The length of the basicranial axis
as to this length； or； in other words； the proportional length of the
line 'g h' to that of 'a b' taken as 100； in the three skulls； is as
follows：Beaver 70 to 100； Lemur 119 to 100； Baboon 144 to 100。 In an
adult male Gorilla the cerebral length is as 170 to the basicranial
axis taken as 100； in the Negro （Fig。 29） as 236 to 100。 In the
Constantinople skull （Fig。 29） as 266 to 100。 The cranial difference
between the highest Ape's skull and the lowest Man's is therefore very
strikingly brought out by these measurements。 In the diagram of the
Baboon's skull the dotted lines 'd1 d2'； etc。； give the angles of the
Lemur's and Beaver's skull； as laid down upon the basicranial axis of
the Baboon。 The line 'a b' has the same length in each diagram。
In such a mammal as a Beaver （Fig。 28）； a line （'a b'。） drawn through
the bones； termed basioccipital； basisphenoid； and presphenoid； is very
long in proportion to the extreme length of the cavity which contains
the cerebral hemispheres （'g h'。）。 The plane of the occipital foramen
（'b c'。） forms a slightly acute angle with this 'basicranial axis；'
while the plane of the tentorium （'i T'。） is inclined at rather more
than 90 degrees to the 'basicranial axis'； and so is the plane of the
perforated plate （'a d'。）； by which the filaments of the olfactory nerve
leave the skull。 Again； a line drawn through the axis of the face；
between the bones called ethmoid and vomerthe 〃basifacial axis〃 （'f
e'。） forms an exceedingly obtuse angle； where； when produced； it cuts
the 'basicranial axis。'
If the angle made by the line 'b c'。 with 'a b'。； be called the
'occipital angle；' and the angle made by the line 'a d'。 with 'a b'。 be
termed the 'olfactory angle；' and that made by 'i T'。 with 'a b'。 the
'tentorial angle；' then all these； in the mammal in question； are nearly
right angles； varying between 80 degrees and 110 degrees。 the angle 'e
f b'。； or that made by the cranial with the facial axis； and which may
be termed the 'cranio…facial angle；' is extremely obtuse； amounting； in
the case of the Beaver； to at least 150 degrees。
But if a series of sections of mammalian skulls； intermediate between a
Rodent and a Man （Fig。 28）； be examined； it will be found that in the
higher crania the basicranial axis becomes shorter relatively to the
cerebral length； that the 'olfactory angle' and 'occipital angle'
become more obtuse； and that the 'cranio…facial angle' becomes more
acute by the bending down； as it were； of the facial axis upon the
cranial axis。 At the same time； the roof of the cranium becomes more
and more arched； to allow of the increasing height of the cerebral
hemispheres； which is eminently characteristic of man； as well as of
that backward extension； beyond the cerebellum； which reaches its
maximum in the South America Monkeys。 So that； at last； in the human
skull （Fig。 29）； the cerebral length is between twice and thrice as
great as the length of the basicranial axis； the olfactory plane is 20
degrees or 30 degrees on the 'under' side of that axis； the occipital
angle； instead of being less than 90 degrees； is as much as 150 degrees
or 160 degrees； the cranio…facial angle may be 90 degrees or less； and
the vertical height of the skull may have a large proportion to its
length。
It will be obvious； from an inspection of the diagrams； that the
basicranial axis is； in the ascending series of Mammalia； a relatively
fixed line； on which the bones of the sides and roof of the cranial
cavity； and of the face； may be said to revolve downwards and forwards
or backwards； according to their position。 The arc described by any
one bone or plane； however； is not by any means always in proportion to
the arc described by another。
Now comes the important question； can we discern； between the lowest and
the highest forms of the human cranium anything answering； in however
slight a degree； to this revolution of the side and roof bones of the
skull upon the basicranial axis observed upon so great a scale in the
mammalian series？ Numerous observations lead me to believe that we must
answer this question in the affirmative。
The diagrams in Figure 29 are reduced from very carefully made diagrams
of sections of four skulls； two round and orthognathous； two long and
prognathous； taken longitudinally and vertically； through the middle。
The sectional diagrams have then been superimposed； in such a manner；
that the basal axes of the skulls coincide by their anterior ends； and
in their direction。 The deviations of the rest of the contours （which
represent the interior of the skulls only） show the differences of the
skulls from one another； when these axes are regarded as relatively
fixed lines。
The dark contours are those of an Australian and of a Negro skull： the
light contours are those of a Tartar skull； in the Museum of the Royal
College of Surgeons； and of a well developed round skull from a
cemetery in Constantinople； of uncertain race； in my own possession。
It appears； at once； from these views； that the prognathous skulls； so
far as their jaws are concerned； do really differ from the
orthognathous in much the same way as； though to a far less degree
than； the skulls of the lower mammals differ from those of Man。
Furthermore； the plane of the occipital foramen （'b c'） forms a
somewhat smaller angle with the axis in these particular prognathous
skulls than in the orthognathous； and the like may be slightly true of
the perforated plate of the ethmoidthough this point is not so
clear。 But it is singular to remark that； in another respect； the
prognathous skulls are less ape…like than the orthognathous； the
cerebral cavity projecting decidedly more beyond the anterior end of the
axis in the prognathous； than in the orthognathous； skulls。
It will be observed that these diagrams reveal an immense range of
variation in the capacity and relative proportion to the cranial axis；
of the different regions of the cavity which contains the brain； in the
different skulls。 Nor is the difference in the extent to which the
cerebral overlaps the cerebellar cavity less singular。 A round skull
（Fig。 29； 'Const'。） may have a greater posterior cerebral projection
than a long one （Fig。 29； 'Negro'）。
Until human crania have been largely worked out in a manner similar to
that here suggesteduntil it shall be an opprobrium to an ethnological
collection to possess a single skull which is not bisected
longitudinallyuntil the angles and measurements here mentioned；
together with a number of others of which I cannot speak in this place；
are determined； and tabulated with reference to the basicranial axis as
unity； for large numbers of skulls of the different races of Mankind； I
do not think we shall have any very safe basis for that ethnological
craniology which aspires to give the anatomical characters of the crania
of the different Races of Mankind。
At present； I believe that the general outlines of what may be safely
said upon that subject may be summed up in a very few words。 Draw a
line on a globe from the Gold Coast in Western Africa to the steppes of
Tartary。 At the southern and western end of that line there live the
most dolichocephalic； prognathous； curly…haired； dark…skinned of
menthe true Negroes。 At the northern and eastern end of the same
line there live the most brachycephalic； orthognathous；
straight…haired； yellow…skinned of menthe Tartars and Calmucks。 The
two ends of this imaginary line are indeed； so to speak； ethnological
antipodes。 A line drawn at right angles； or nearly so； to this polar
line through Europe and Southern Asia to Hindostan； would give us a
sort of equator； around which round…headed； oval…headed； and
oblong…headed； prognathous and orthognathous； fair and dark racesbut
none possessing the excessively marked characters of Calmuck or
Negrogroup themselves。
FIG。29。Sections of orthognathous （light contour） and prognathous （dark
contour） skulls； one…third of the natural size。 'a b'； Basicranial
axis； 'b c； b1 c1'； plane of the occipital foramen； 'd d1'； hinder end
of the palatine bone； 'e e1'； front end of the upper jaw； 'T T1'；
insertion of the tentorium。
It is worthy of notice that the regions of the antipodal races are
antipodal in climate； the greatest contrast the world affords； perhaps；
being that between the damp； hot； steaming； alluvial coast plains of
the West Coast of Africa and the arid； elevated steppes and plateaux of
Central Asia； bitterly cold in winter； and as far from the sea as any
part of the world can be。
From Cen