304 



NATURE 



[November 13, 1919 



Morris (Brii. Med. Journ., i., p. 1038, 1913), "the ' 

 skin is cold, dry, and rough, seldom or never per- 

 spires, and may take on a yellowish tint; there is 

 a bright red flush in the malar region. The skin as 

 a whole looks transparent ; the hair of the scalp 

 becomes scanty ; the pubic and axillary hair, with the 

 eyelashes and eyebrows, often falls out; in many 

 cases the teeth are brittle and carious. All these 

 appearances disappear under the administration of 

 thyroid extract." We have here conclusive evidence 

 that the thyroid acts directly on the skin and hair, 

 just the structures we employ in the classification of 

 human races. The influence of the thyroid on the 

 development of the other systems of the body, par- 

 ticularly on the growth of the skull and skeleton, is 

 equally profound. This is particularly the case as 

 regards the base of the skull and the nose. The 

 arrest of growth falls mainly on the basal part of the 

 skull, with the result that the root of the nose appears 

 to be flattened and drawn backwards between the 

 eyes, the upper forehead appears projecting or bulg- 

 ing, the face appears flattened, and the bony scaf- 

 folding of the nose, particularly when compared with 

 the prominence of the jaws, is greatly reduced. Now 

 these facial features which I have enumerated give 

 the Mongolian face its characteristic aspect, and, to 

 a lesser degree, they are also to be traced in the 

 features of the Negro. Indeed, in one aberrant 

 branch of the Negro race — the Bushman of South 

 Africa — the thyroid facies is even more emphatically 

 brought out than in the most typical Mongol. You 

 will observe that, in my opinion, the thyroid — or a 

 reduction or alteration in the activity of the thyroid — 

 has been a factor in determining some of the racied 

 characteristics of the Mongol and the Negro races. 

 I know of a telfing piece of evidence which supports 

 this thesis. Some years ago there died in the East 

 End of London a Chinese giant — the subject, we must 

 suppose, of an excessive action of the pituitary gland 

 — the gland which I regard as playing a predominant 

 part in shaping the face and bodily form of the Euro- 

 pean. The skeleton of this giant was prepared and 

 placed in the Museum of the London Hospital Medical 

 College by Col. T. H. Openshaw, and anyone inspect- 

 ing that skeleton can see that, although certain 

 Chinese features are still recognisable, the nasal 

 region and the supra-orbital ridges of the face have 

 assumed the more prominent European type. 



There are two peculiar and very definite forms of 

 dwarfism with which most people are familiar, both 

 of which must be regarded as due to a defect in the i 

 growth-regulating mechanism of the thyroid. Now, ' 

 one of these forms of dwarfism is known to medical 

 men as achondroplasia, because the growth of car- 

 tilage is particularly affected, but in familiar language 

 we may speak of the sufferers from this disorder of 

 growth as being of the "bulldog breed" or of the 

 "dachshund breed." In the dachshund the limbs ! 

 are greatly shortened and gnarled, but the nose or i 

 snout suffers no reduction, .while in the bulldog the 

 nose and nasal part of the face are greatly reduced ; 

 and withdrawn, showing an exaggerated degree of 

 Mongolism. Among achondroplastic human dwarfs j 

 both breeds occur, but the "bulldog" form is much [ 

 more common than the " dachshund " type. The 1 

 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 anthropo- | 

 logists, seeing that short limbs and a long trunk are j 

 well-recognised racial characteristics of the Mongol. | 

 In the second kind of dwarfism, which we have reason : 

 to regard is due to a functional defect of the thvroid, ! 

 the Mongolian traits are so apparent that the sufferers ' 

 from this disorder are known to medical men as " Mon- 

 NO. 261 I, VOL. 104] 



golian idiots " — for not only is their growth stunted, 

 but their brains also act in a peculiar and aberrant 

 manner. Dr. Langdon Down, who gave the subjects 

 of this peculiar disorder the name " Mongolian 

 idiots " fifty-five years ago, knew nothing of the 

 modern doctrine of internal secretions, but that doc- 

 trine has been applied m recent years by Dr. F. G. 

 Crookshank ("The Universal Medical Record," 

 vol. iii., p. 12, 1913) 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 elements ; 

 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 goriUine 

 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 Ly 

 the theory, at one time very popular, that a Mon- 

 goloid race had at one time spread over Europe, and 

 that Mongoloid traits were atavistic recurrences. .\n 

 examination of the human remains of ancient Eurcpe 

 yields no evidence in support of a Turanian or Mongol 

 invasion of Europe 



All these manifestations to which I have been 

 directing \our attention — the sporadic manifestation of 

 Mongoloid characters in diseased 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 explained by the theory I am 

 supporting, namely, that the conformation of man 

 and ape and of everv vertebrate animal is determined 

 by a common growth-controlling mechanism which is 

 resident in a system of small but complex glandular 

 organs. We must now look somewhat more closely 

 into the manner in which this growth-regulating 

 mechanism actually works. That we can do best 

 bv taking a glimpse of a research carried out by 

 Bayliss and Starling in the opening years of (he 

 present century. Thev were seeking to explain why 

 it was that the pancreas poured out its digestive juice 

 as soon as the contents of the stomach commenced 

 to pass into the first part of the duodenum. It_ \yas 

 then known that if acid was applied to the lining 

 epithelial membrane of the duodenum, the pancreas 

 commenced to work ; it was known also that the 

 message which set the pancreas into operation was 

 not conveyed from the duodenum to the pancreas by 

 nerves, for when thev were cut the mechanism was 

 still effective. Bayliss and Starling solved the puzzle 

 by making an emulsion from the acid-soaked lining 

 epithelium of the duodenum and injecting the extract 

 of that emulsion into the circulating blood. Tlie 

 result was that the pancreas was immediately thrown 

 into activity. The particular substance which was 

 thus set circulating in the blood and acted on the pan- 

 creas, and on the pancreas alone, and thus served as a 

 messenger or hormone, they named secretin. Thev not 

 only cleared up the mechanism of pancreatic secre- 

 tion , but at the same time made a discovery of much 

 greater importance. They had discovered a new 

 method whereby one part of the human bodv could 

 communicate with and control another. Up to that 

 time we had been like an outlandish visitor to a 

 strange city, who believed that the visible telegraph 

 or telephone wires were the only means of com- 



