ENDOCRANIAL CASTS OF THE GIRAFFIDAE ; 301 
DESCRIPTION OF SPECIMENS 
(a) Giraffa camelopardalis (figures 1 to 3 and 17 to 19) 
As the morphology of the giraffe brain is well known through 
the work of Krueg (22), Elliot Smith (9) and others, and the 
osteology of the skull has received special attention in the memoirs 
of Sir Ray Lankester (23 and 24) and Julien Fraipont (17), 
this cast affords excellent material upon which to begin the 
present study. 
Only a few accurate observations upon the weight of the 
brain and the total body weight of the giraffe have been recorded. 
I quote the following figures from Max Weber (29). 
Body Weight Brain Weight Ratio 
(1) Male, two months old.... 150,000 grams 389 grams 1392 
(2) Male, young adult....... . 800,000 grams 420 grams 1: 761 
(ayia vMisdle “adult... «20am 529,000 grams 680 grams TENT 
The volume of the cast described here is 650 ec., but no record 
as to the total body weight of this specimen could be obtained. 
Taking it for granted that the specific gravity of nervous tissue 
in.the giraffe is but little different from that in man, the approxi- 
mate calculated weight of this brain would be 575 grams. 
A study of the data recorded by Weber for the giraffe and of 
the ratios which obtain between the brain and body weight in 
the horse as cited by Flatau and Jacobson (12!), makes it evident 
that, in these two species the relationship of brain weight to body 
weight is approximately the same in adult animals of equal bulk. 
The transverse diameter of the cast is greatest in the parietal 
region, where it measures 116 mm. across. From the basi- 
1The further statement of these authors (l.c., p. 527) that the volume of the 
brain compared with that of the skull is lower among ungulates than in any other 
group of mammals is of interest. In this heterogeneous group the ratio varies 
from 1:7 in the horse up to 1:10 in the elephant. This phenomenon may be 
correlated to some extent with the presence in certain members of the group of 
heavy defensive head appendages. However, it is much more probably the 
direct result of the herbivorous habit common to all these animals, which has 
given rise to the acquisition of a complicated dental mechanism and part passu 
along with this, a facial development for its accommodation. 
