302 



NATURE 



[November 13, 1919 



fashions her biological patterns. We have replaced 

 the creative finger by the evolutionary machine, but 

 no one is more conscious of the limitations of that 

 machine than the student of human races. We are 

 all familiar with the features of that racial human 

 type which clusters round the heart of Africa ; we 

 recognise the Negro at a glance by his black, shining, 

 hairless skin, his crisp hair, his flattened nose, his 

 widely opened dark eyes, his heavily moulded lips, his 

 gleaming teeth and 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 unpractised eye, clearly different from the 

 Mongolian native of North-Eastern Asia; the skin, 

 the hair, the eyes, the quality of brain and voice, the 

 carriage of body and proportion of limb to bodv pick 

 out the Mongol as a sharplv differentiated human 

 type. Different from either of these is the native of 

 Central Europe — the Aryan or Caucasian type cf 

 man ; we know him by the paleness of his skin and 

 by his facial features — particularly his narrow, pro- 

 minent nose and thin lips. We are so accustomed to 

 the prominence of the Caucasian nose that onlv a 

 Mongol or Negro can appreciate its singularity in 'our 

 Aryanised world. When we ask how these three 

 types — the European, Chinaman, and Negro — came 

 by their distinctive features, we find that our ev'olu- 

 tionary machine is defective; the processes of natural 

 and of sexual selection will preserve and exai7£<erate 

 traits of body and of mind, but thev cannot produce 

 that complex of features which marks off one racial 

 type from another. Nature has at her command 

 some secret mechanism bv 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 d;w. but which we are now bc£?inning 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 1 

 prooose to make the subject of mv 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 

 recognise as parts of the machinery which regulate 

 the growth of the body. They form merelv a fraction 

 of the body — not more than i/j8oth part of it : a 

 man might pack the entire series in his watch-oocket. 

 The modern medical student is familiar with each 

 one of them — the pituitarv 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 thvroid in the 

 neck, set astride the windpipe, forms a more bulky 

 mass ; the two suprarenal bodies situated in the l>elly, 

 capping the kidneys, and the interstitial elands em- 

 bedded within the substance of the testicle and ovary, 

 complete the list. The modern phvsician is also 

 familiar with the fact that the growth of the bodv 

 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 thirtv-three 

 years now since first one woman and then another 

 came to Dr. Pierre Marie in Paris seeking relief from 

 a persistent headache, and mentioning incidentallv 

 that their faces, bodies, hands, and feet had aftered 

 somuch in recent years that their best-known friends 

 failed to recognise them. That incident marked the 

 commencement of our knowledge of the pituilarv 

 gland as an intrinsic oart of the machinery which 

 regulates the shaping of our bodies and features. Dr. 

 Marie named the condition acromegalv. .Since then 

 hundreds of men and women showing symptoms 

 similar to those of Dr. Marie's patients have been 

 NO. 261 1, VOL. 104] 



seen and diagnosed, and' in every instance where the 

 acromegalic changes were typical and marked there 

 has been found a definite enlargement or tumour of 

 the pituitary body. The practised eye recognises the 

 full-blown condition of acromegaly at a glance, so 

 characteristic are the features of the sufferers. Nay, cs 

 we walk along the streets we can note slight degrees 

 of it — degrees which fall far short of the border- 

 line of disease ; we note that it may give charac- 

 teristic traits to a whole family — a family marked bv 

 what may l)e named an acromegalic taint. The 

 pituitary gland is also concerned in another disturb- 

 ance of growth — giantism. In every case where a 

 young lad has shot up, during his late "teens," into 

 a lanky man of seven feet or more — has liecome .1 

 giant — it has been found that liis pituitary gland w.i^ 

 the site of a disordered enlargement. The pituitarv 

 is part of the mechanism which regulates our stature . 

 and stature is a racial characteristic. The giant is 

 usually acromegalic as well as tall, but the two condi- 

 tions need not be combined ; a young lad may undergo 

 the bodilv changes which characterise .acromegaly and 

 yet not become abnormally tall, or he may become — 

 although this is rarely the case — a giant in stature 

 and vet may not assume acromegalic features. There 

 is a third condition of disordered growth in which the 

 pituitarv is concerned — one in which the length of the 

 limbs is disproportionately increased — in which the 

 sexual system and .all the secondary sexual characters 

 of bodv and mind either fail to develop or disappear- - 

 where fat tends to be deposited on the body, par- 

 ticularly over the buttocks and thighs- -where, in 

 brief, a eunuchoid condition of body develops. In 

 all these three conditions we seem to be dealing 

 with a disordered and exaggerated action of the 

 pituitary gland ; there must be conditions of an 

 opposite kind where the functions of the pituitary are 

 disordered and reduced. . .\ number of cases of 

 dwarfism have been recorded where boys or girls 

 retained their boyhood or girlhood throughout life, 

 : apparently because their pituitary gland had been 

 invaded and partly destroyed by tumours. We shall 

 see that dwarfism may ri^sult also from a failure of 

 the thyroid gland. On the evidence at our disposal, 

 evidence which is being rapidly augmented, we art 

 justified in regarding the pituitary gland as one ot 

 the principal pinions in the machinery which regulate? 

 the growth of the human body and is directly con 

 cerned in determining stature, cast of features, tex 

 ture of skin, and character of hair — all of them marks 

 of race. When we compare the three chief racial 

 types of humanity — the Negro, the Mongol, and the 

 Caucasian or European — we can recognise in the last- 

 named a greater predominance of the pituitary than 

 in the other two. The sharp and pronounced nasalisa- 

 tion of the face, the tendency to strong eyebrow 

 ridges, the prominent chin, the tendency to bulk of 

 body and height of stature in the majority of Euro- 

 peans, is best explained, so far as the present state 

 of our knowledge goes, in terms of pituitary function. 

 There is no question that our interest in the 

 mechanism of growth has been quickened in recent 

 years by observations and discoveries made by 

 physicians on men and women who suffered from 

 pituitary disorders, but that a small part of the body 

 could influence and regulate the growth and charac- 

 terisation of the whole was known in ancient times. 

 For manv centuries it has been common knowledge 

 that the removal of the genital glands alters the 

 external form and internal nature of man and 

 beast. The sooner the operation is performed after 

 birth, the more certain are its effects. Were a 

 naturalist from a unisf-xual world to visit this earth 

 of ours it would be difficult to convince him that a 



