794 THE AMERICAN JOURNAL OF SOCIOLOGY
transitions represented in the most diverse degrees by the dif- ferent varieties of the human population, while between the Namquian and the chimpanzee the difference is absolute and abrupt.
The cerebral angle gives indications of like significance :
Lower Bretons 159
Namaquian - 152
Chimpanzee - 116
Between the two there is a series of transitions. Between the highest human development and the lowest development in monkeys there is a marked discontinuity. The cubage of the cranial capacity varies from 1,600 to about 1,200 c.c. in the human species, falling rapidly to 439 c.c. in the orang-outang, and to 421 c.c. in the chimpanzee. There is no actual transition between man and the anthropoid apes, at least in the analogous varieties.
Broca has observed that the average cranial capacity of the Parisians of the twelfth century is inferior to that of the nine- teenth century; that the skulls of the nobility of the first epoch are larger than those of the plebeians of the same epoch ; that the skulls of the attendants in the hospitals are smaller than those of the students of medicine and pharmacy; that the skulls of the factory workers at Clichy (the work being almost auto- matic) are smaller than those of carpenters and joiners ; that the cranial capacity of males is generally much larger than that of females ; etc., etc. Despite this large secondary variability, the extreme oscillations average only about 300 c.c. in the entire human species, and these tend to be reduced as the inferior vari- eties become extinct or civilized ; at the same time, the organ certainly loses its plasticity in the superior varieties as it is per- fected and as heredity fixes its structure.
The classification of the following populations can, therefore, be made from the point of view of the average cranial capacity. The cranial capacity of the Pithecanthropus of Java, 900- 1,000 c.c. , is an intermediary form between the gibbons and the most inferior human race known, the Neanderthal (Mortillet):
