Kathleen V. Rylby and Julia Bell 
435 
(13) Concluding Remarks. We arc aware how much of the present paper is 
open to criticism on account of the limited number of the racial series dealt with 
and the sparseness of the individual crania in those series. Notwithstanding we 
hope that the reader may find suggestive paths leading off from these preliminary 
researches. Wc believe that the time must come when in the larger Universities 
there will exist established schools of craniometry with adequate anatomical, 
physical and statistical training, and that such schools will carry on secular work 
in collecting and measuring. We have indicated in this paper that the study of 
the personal equation of craniometricians has hardly begun, but we look forward 
to the day when it will be as customary for one of the workers in an established 
craniometry laboratory to be adopted as a standard and his personal equation 
relative to other workers at home and abroad discussed, as it is for one astro- 
nomical observer to be tested against a second. The intercomparability of 
measurements is largely taken on blind trust by craniologists to-day. Only when 
relative personal equation has been studied will it be possible safely to pool the 
measurements of small series made by different laboratories. 
Again, anatomical and zoological museums and collections are singularly 
defective at the present time. If it were desirable to make a thorough study of 
the cranium of any animal other than man — say dog or horse — is there any collec- 
tion which could place at the disposal of the inquirer a hundred crania of definite 
sex, fairly uniform age and reasonable limits of race ? We sadly fear not, and yet 
how much could be learnt of evolutionary descent by an exact study of a variety 
of species based on even a hundred crania from each ! Take the plane of the 
foramen magnum, determined say by a plane through basion and opisthion perpen- 
dicular to the sagittal plane, and consider the angle this makes with the horizontal 
plane of the skull, as determined, say, by the Frankfurt Concordat. This angle 
— closely allied to Dauberton's angle — is of very great evolutionary importance, but 
who can say — on the basis of really numerically adequate measurements* and other 
than from mere impression gained on a few specimens — what its value is in the chief 
mammals, in the anthropoid apes, in negroes and in the various other races of man? 
Comparative craniometry is almost at its origins if we refer, not to descriptions of 
" typical "f crania, but to the measurement of numerically adequate series. Not until 
investigations, only roughly foreshadowed in such a paper as the present, have been 
made on a far greater variety of species and on a wide range of cranial characters — 
and this will have to wait until adequate material accumulates in our museums — 
would any suggestion of evolutionary descent pass into comparative certainty. 
When the reader realises that some 25 gorilla skulls of one sex, but of all ages 
* We do not wish for a moment to underrate Broca's work in this field ; but besides his views as to 
the horizontal planes, his series are often unsexed, and, especially for the chief mammals, wholly 
inadequate numerically. Thus he uses two or three apes, dogs, cats, and so forth, where we need 50 to 
100 of each breed and sex. 
t How few anatomists realise that nobody knows what a " typical" cranium is until a long series of 
the particular race has been measured ! We remember seeing in one museum a skull, labelled "typical 
English," and this at a date when not 50 English crania from one district and period had been 
measured. 
