The entire adult skeleton consists of 200 distinct bones, as follows:
| The spine or vertebral column | |
| (sacrum and coccyx included) | 26 |
| Cranium | 8 |
| Face | 14 |
| Os hyoids, sternum and ribs | 26 |
| Upper extremities | 64 |
| Lower extremities | 62 |
| 200 |
The patellæ are included as separate bones; the smaller sesamoid bones and the ossicula auditus are not counted. The teeth belong to the tegumentary system.
BLOOD-CORPUSCLES.
The average number of red blood-corpuscles per cubic millimeter is about 5,000,000 for men, and somewhat less for women. The number is much increased in people who live in altitudes of about 8000 feet or more. The greatest decrease occurs in anemia, when they may number less than 1,000,000, and in leukemia, when there may be not more than 2,000,000.
The average number of white blood-corpuscles per cubic millimeter varies from 5000 to 10,000. The number is usually decreased in anemia, and much increased in leukemia, when they may number 500,000 per cubic millimeter.
Blood should contain 100 per cent. hemoglobin. Hospital patients seldom have this amount. Patients are not considered safe for operation who have less than 50 per cent., and can not live long if they have 10 per cent. or less.
The skeleton.
