STUDY OF MAN 845
making chemical analyses of them, etc., if it is not to give a deeper knowledge of them and thereby learn more about our planet. So the patient and extended study of man, especially children, is to gain more definite knowledge about him and a deeper insight into his nature. The time has certainly come when man, as he is, should be studied as much as nature.
RECENT CONCLUSIONS.
As an illustration of some results from recent studies of modern man, we give a number of conclusions of investigators from different parts of the world.
Some of the statements may appear to be of little utility, but, as the history of science has often shown, the real value of a single truth may not be known until other, cognate truths are discovered. These conclusions, of course, are to be taken in a general sense only ; that is, they are true in most of the cases investigated :
Maximum growth in height and weight occurs in boys two years later than in girls (Bowditch).
First-born children excel later-born in stature and weight (Boas).
Healthy men ought to weigh an additional 5 pounds for every inch in height beyond 61 inches, at which height they ought to weigh 120 pounds (Lancaster).
Chest-girth increases constantly with height, and is generally half the length of the body (Landsberger).
Chest-girth and circumference of head increase in parallel lines (Daffner) .
The relatively large size of head as compared with body in children may be due to the fact that from birth on the child needs its brain and senses as much as when it is grown (Weis- senberg).
Boys grow more regularly than girls, but the growth of girls during school years is greater than that of boys (Schmidt) .
In boys in school the muscles of the upper extremities increase with age as compared with those of the lower extremi- ties, because of their sitting more than standing (Kotelmann).
