PRIMROSE : THE ANATOMY OF THE ORANG OUTANG 
17 
of the Gorilla in this respect more closely resembles the hand of man 
than does the hand of the Orang. 
The great length and narrowness of the hand has been referred to ; it 
is quite obvious, however, that the fingers of the Orangare disproportion- 
ately short as compared with the greatly elongated palm. The cause of 
this is demonstrated by Langer^ in his dissection of an interdigital 
membrane which spreads out over the upper fourth of the proximal 
phalanx of the four inner digits. This membrane is not present in man^ 
and in the Orang, therefore, more of the proximal phalanx is sunken 
into the palm than is the case in man. The result is that the fingers of 
the Orang appear proportionately short. Another effect will be observed 
by reference to the photographs here reproduced, namely, that the integ- 
umentary grooves are further separated from the interdigital clefts in 
the Orang than they are in man. 
Dr. Blake, ^ in his observations on the study of the hand for indica- 
tions of disease, has noted the remarks made by Dr. Harry Campbell 
regarding the curious resemblance between the acquired bone and 
skin changes in the acromegalous subject, and the condition normal 
in the hand of the Gorilla. It would appear that many of the mor- 
bid changes in this disease bring about conditions of the character 
referred to, and Blake would view such as examples apparently of 
reversion to a primitive arboreal type. Whilst I am not prepared to 
seriously entertain this idea, there is no doubt of the fact, at all events 
that in this disease the hand of man comes to present a curiously close 
resemblance, in appearance, to the hand of the Gorilla. 
Turning now our attention to the markings in the sole of the foot, 
we find that in the human foot these are largely obliterated after the 
individual has walked about, and pressure has been brought to bear 
upon the sole, the skin becoming as a result thick and indurated. 
Some interesting observations on these integumentary markings, as they 
appear in the foot of the infant, have been made by Dr. Louis 
RobinsonHn the “ Nineteenth Century.” He looks upon the markings 
on the infant’s foot as giving some evidence of the evolution of the 
human foot from a structure which at one time was able to grasp an 
object after the manner of the human hand or the foot of an anthropoid 
ape. Robinson states that these lines are scarcely visible at fourteen 
months and are only present in a few cases after two years of age, 
1 Loc. cit., pp. 182 and 185. 
2 Edward Blake, M.D., “On the Study of the Hand for Indications of Local and General Disease,’’ 
London, 1889, p. 36. 
3 Louis Robinson, M.D., “ The Meaning of a Baby’s Footprint.’’ The Nineteenth Century, Vol. 
XXXI, 1892, p, 795. 
