526 
DE. J. BAENAED DAVIS ON THE WEIGHT OF THE BEAIN 
25. Maoris *. 
In conclusion, a hope may be expressed that this investigation has shown that some 
confidence may be placed in the method which has been followed ; and that there is 
reason to think this communication may prove a valid contribution to the important and 
interesting subject of the weight of the brain in the different Races of Man. 
Postscript. 
[Deceived July 31, 1868.] 
The value of this communication, so far as it turns upon the proposed tare employed 
in its calculations, has received an important illustration, which must be alluded to here. 
The great politeness of an eminent Austrian anatomist, Dr. A. Weisbach, of Vienna, 
has afforded the means of testing this validity in a more complete manner than could 
be expected to occur in this country. He has taken the encephala out of 115 skulls of 
males and females, and carefully weighed them ; subsequently, when the cranium was 
prepared, he has gauged its capacity in each case. The data he has thus obtained, he 
has had the goodness to communicate. They afford the chief materials for the following 
Table. The capacity is given in cubic centimetres first, then the estimated weight of the 
brain as deduced from our method, next the actual weight of the brain, without mem- 
branes, fluids and medulla oblongata , as determined by Dr. Weisbach. In order to 
compensate for this deficiency of the medulla oblongata, an addition of 14 grms., or 
half an ounce av., is made to each mean, so as to show in the next column the real 
weight of the entire brain. By this addition it is believed that we shall compensate as 
nearly as may be necessary for the absence of the medulla oblongata, which constitutes 
a portion of the contents of the skull. Professors Quain and Sharpey, quoting 
from Dr. Reid, state that the pons Varolii and medulla oblongata conjointly weigh in 
men 15f drs. av., in women 1 oz. and a quarter of a dr.f. By Dr. Robert Boyd it is 
said, “ the average weight of the pons Varolii and medulla varied in the males from 
1T5 oz. to 1'02 oz., and from T05 to - 95 oz. in the females”^. Considering these ob- 
servations to prove that these two portions of the contents of the cranium, the pons 
Varolii, and the medulla oblongata, weigh on the average about an ounce, we may con- 
veniently regard them as each weighing half an ounce. The last column of the Table 
shows the exact average amount of the deficiency, or of the excess, of our estimated 
weight of the brain, in relation to that obtained by Dr. Weisbach’s experiments. 
* The mean stature of 3 New Zealand men was found by Dr. Weisbach to be 1757 millims., or 5 feet 9-2 
inches. 
t Elements of Anatomy, 5th ed., 1848, vol. ii. p. 672. 
X Philosophical Transactions, 1861, p. 262. 
