444. ANNUAL REPORT SMITHSONIAN INSTITUTION, 1919. 
strong jaws. He has a carriage and proportion of body of his own; 
he has his peculiar quality of voice and action of brain. He is, even 
to the unpracticed eye, clearly different from the Mongolian native of 
northeastern Asia ; the skin, the hair, the eyes, the quality of brain and 
voice, the carriage of body and proportion of limb to body serve to 
pick out the Mongol as a sharply differentiated human type. Differ- 
ent from either of these is the native of central Kurope—the Aryan or 
Caucasian type of man; we know him by the paleness of his skin 
and by his facial features—particularly his narrow, prominent nose 
and thin lips. We are so accustomed to the prominence of the Cau- 
casian nose that only a Mongol or Negro can appreciate its singu- 
larity in our Aryanized world. When we ask how these three 
types—the European, Chinaman, and Negro—came by their dis- 
tinctive features, we find that our evolutionary machine is defective ; 
the processes.of natural and of sexual selection will preserve and 
exaggerate traits of body and of mind, but they can not produce 
that complex of features which marks off one racial type from an- 
other. Nature has at her command some secret mechanism by which 
she works out her new patterns in the bodies of man and beast—a 
mechanism of which we were almost ignorant in Darwin’s day, but 
which we are now beginning to perceive and dimly understand. It 
is the bearing of this creative or morphogenetic mechanism on the 
evolution. of the modern races of mankind which I propose to make 
the subject of my address. 
Hid away in various parts of the human frame is a series of more 
or less obscure bodies or glands, five in number, which, in recent 
times, we have come to recognize as parts of the machinery which 
regulate the growth of the body. They form merely a fraction of 
the body—not more than one one-hundred-and-eightieth part of it; 
a man might pack the entire series in his watch pocket. The modern 
medical student is familiar with each one of them—the pituitary 
body, about the size of a ripe cherry, attached to the base of the 
brain and cradled in the floor of the skull; the pineal gland, also 
situated in the brain, and in point of size but little larger than a 
wheat grain; the thyroid in the neck, set astride the windpipe, forms 
a more bulky mass; the two suprarenal bodies situated in the belly, 
capping the kidneys, and the interstitial glands embedded within 
the substance of the testicle and ovary, complete the list. The mod- 
ern physician is also familiar with the fact that the growth of the 
body may be retarded, accelerated, or completely altered if one or 
more of these glands become the seat of injury or of a functional 
disorder. It is 33 years now since first one woman and then another 
came to Dr. Pierre Marie in Paris seeking relief from a persistent 
headache and mentioning incidentally that their faces, bodies, hands, 
