J. Blakeman 
129 
Here in the latter two groups adults, 21 years and over, have been taken, while 
in the hospital group among the males 24 was the minimum admitted age. Clearly 
we have to deal, even allowing for a larger percentage of accidents and an absence 
of some of the diseases of old age, for a population of lesser constitutional vitality 
as measured by expectation of life. It is to be noted that the female is shorter- 
lived than the male*. 
For the horizontal circumference we have no reliable data for comparison. 
Dr Beddoe gives itf for 30 groups, containing various numbers from two to a 
hundred, and also for a hundred individuals, but in not one single case of the groups 
or of the individuals has lie obtained a result as low as our mean of 558 mm. On 
the other hand it is almost exactly the value 560 Lewenz and Pearsonj have found 
for Jeremy Bentham's head, which in other respects is close to the English mean 
type. There appears to be little doubt accordingly that Dr Beddoe has an 
individual method of measuring this circumference. 
Lastly, turning to the brain-weights, we have, pooling the results of Reid and 
Peacock, Clendenning, and Sims, the following mean values. 
TABLE VIL 
English Brain-iueights in gvms. 
Group 
? 
Gladstone's Middlesex Hospital Data 
Reid and Peacock, Clendenning, Sims§ ... 
1328 
133.5 
1224 
1235 
Thus the average brain-weight of an English general hospital population 
appears to be fairly constant when we compare Gladstone's data with the means 
of other material. But this is of course no evidence that the general hospital 
population is at all representative of the general population. 
On the contrary, the fact that for the head diameters, for stature, and for 
constitutional robustness, as measured by duration of life, the hospital population 
falls below the general population, would lead us to believe that it probably does 
so in brain-weight ; and we should atti'ibute the probable source of this differentia- 
tion to want of nourishment and " shrinkage " due to chronic disease. 
(4) Variation Constants. 
Turning first to the head measurements we may compare our results with those 
for other English groups. This is done in Table VIII. 
* On this point see " Assortative Mating in Man," BiometriUa, Vol. it. p. 488. 
t UAntliropologie, Vol. xiv. pp. 284, 291 — 4. 
X Biometrika, Vol. iii. p. 394. 
§ Pearson: The Chances of Death, Vol. i. p. 321. Of course the pooling of the results of these 
(different observers is open to considerable criticism. 
Biometrika iv 17 
