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orifice, not only in man, but in all Primates. In the lower apes this 
wall soon disappears, in the foetus of anthropoids on the other hand 
it continues to exist, as appears from the observations of DENIKER, 
Sperino, myself, and others, so that the older foetus of these apes 
has, in front of the vestibulum a mons veneris and at the sides labia 
majora, be it that they are not nearly so strongly developed as in man. 
After birth these characters seem to disappear soon, also in anthro- 
poids, in man they continue to exist. So we have here again a typical 
human character, which is nothing but a persisting foetal property. 
And here also we are struck by the fact that the difference 
between man and the apes is the result of a developmental retard- 
ation, but now of a somewhat different character from the preceding 
cases. For though in the other Primates the genital wall disappears 
at last, and the disappearance is therefore the normal process, it 
continues to exist in man and increases in size in accordance with 
the general growth. So here the retardation did not mean the sup- 
pression of the coming about of a morphological character, but the 
prevention of the disappearance of a very early condition. Which 
endocrine organ may be thought of in relation to this phenomenon? 
By many clinical observations we are able to answer also this 
question. It is almost certain that we must here think of the influ- 
ence of glandula thyroidea. Congenital absence, or too slight . 
development of this gland is accompanied by an insufficient develop- 
ment of the exterior genitals, the labia majora and the mons veneris 
are sometimes missing. The genital apparatus therefore, has in 
such cases, been formed as in the other Primates, the specifical 
human character having developed in an insufficient manner. The 
influence of Glandula thyroidea on this human character appears 
further from the fact that after extirpation of this endocrine organ 
atrophy of the genitals is resulting, adhibition of the extract of this 
gland brings atrophied or insufficiently developed external genitals to 
a stronger development. 
The case that we have last discussed forms a welcome transition 
to a specifical human charactar, that I now want to discuss briefly 
and with which I shall conclude the casuistic part of my contribu- 
tion. The specifically human character par excellence is the great 
weight of the brain. Is this also the result of a retardative influence, 
you will ask somewhat sceptically ? I reply, yes, however paradoxical 
this may sound. 
Let us therefore briefly take a nearer view of the part played 
by the endocrine organs in morphogenesis. This part consists in these 
organs ensuring a harmonious development of the form. An har- 
