BIOMETKICAL STUDIES ON MAN. 
I. VARIATION AND CORRELATION IN BRAIN-WEIGHT*. 
By RAYMOND PEARL, Ph.D. 
CONTENTS. 
PAGE 
1. Introduction 13 
2. Data 16 
3. Fundamental Constants 21 
4. Brain-weight Types 22 
g (Variation in Brain-weight 29 
I Homogeneity of Material ......... 29 
6. On the Nature of the Frequency Distributions ..... 37 
7. The Correlation of Brain-weight with other Characters ... 42 
8. Brain-weight and Sex ..... .... 45 
9. Brain-weight, Age and Stature 51 
10. Brain-weight and Body-weight ........ 64 
.11. Brain-weight and Skull Characters 07 
12. The Weight of the Cerebrum 74 
13. Concluding Remarks .......... 76 
14. Summary ............ 82 
Appendix. Correlation Tables 83-104 
1. Introduction. 
The subject of brain-weight iu man has for a long time been given considerable 
attention by anatomists and anthropologists. The reason for this is obvious. 
Since the brain is the organ of the mind it appeared to earlier workers that size 
of brain ought to be an index of intellectual capacity. The substance of the 
brain is of such physical homogeneity that its weight is a fairly accurate, as well 
as simple, " size " measure of the organ. Consequently, by earlier workers, brain- 
weights were collected, studied and discussed to a considerable extent as measures 
* Contributions from the Zoological Laboratory of the University of Michigan. No. 86. 
