450 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1919, 
Among achondroplastic human dwarfs both breeds occur, ‘but the 
“bulldog” form is much more common than the “ dachshund” type. 
The shortening of limbs with retraction of the nasal region of the 
face—pug-face, or prosopia, we may call the condition—has a very 
direct interest for anthropologists, seeing that short limbs and a long 
trunk are well recognized racial characteristics of the Mongol. In 
the second kind of dwarfism, which we have reason to regard as due 
to a functional defect of the thyroid, the Mongolian traits are so 
apparent that the sufferers from this disorder are known to medicai 
men as “ Mongolian idiots,” for not only is their growth stunted but 
their brains also act in a peculiar and aberrant manner. Dr. Lang- 
don Down, who gave the subjects of this peculiar disorder the name 
“ Mongolian idiots” 55 years ago, knew nothing of the modern doc- 
trine of internal secretions, but that doctrine has been applied in 
recent years by Dr. F. G. Crookshank (The Universal Medical Ree- 
ord, vol. iti, p. 12, 1918) to explain the features and condition of 
Mongoloid imbecile children. Some years ago (Journ. of Anat. and 
Physiol., 1913) I brought forward evidence to show that we could 
best explain the various forms of anthropoid apes by applying the 
modern doctrine of a growth-controlling glandular mechanism. In 
the gorilla we see the effects of a predominance of the pituitary ele- 
ments; in the orang, of the thyroid. The late Prof. Klaatsch tried 
to account for the superficial resemblances between the Malay and 
the orang by postulating a genetic relationship between them; for a 
similar reason he derived the Negro type from a gorilline ancestry. 
Occasionally we see a man or woman of supposedly pure European 
ancestry displaying definite Mongoloid traits in their features. We 
have been in the habit of accounting for such manifestations by the 
theory, at one time very popular, that a Mongoloid race ‘had at one 
time spread over Europe and that Mongoloid traits were atavistic 
recurrences. An examination of the human remains of ancient 
Europe yields no evidence in support of a Turanian or Mongol inva- 
sion of Europe. 
All these manifestations to which I have been directing your atten- 
tion—the sporadic manifestation of the Mongoloid characters in dis- 
eased children and in healthy adult Europeans, the generic characters 
which separate one kind of ape from another, the bodily and mental 
features which mark the various races of mankind—are best ex- 
plained by the theory I am supporting, namely, that the conforma- 
tion of man and ape and of every vertebrate animal is determined by 
a common growth-controlling mechanism which is resident in a sys- 
tem of small but complex glandular organs. We must now look 
somewhat more closely into the manner in which this growth-regulat- 
ing mechanism actually works. That we can do best by taking a 
glimpse of a research carried out by Bayliss and Starling in the open- 
rap aha en MRE NESS Dey ieee vS ~ 
