28 
NATURAL HISTORY. 
Having raised tlie arm by its muscles, the fingers and thumbs grasp an 
, or, in other 
words, certain muscles which are placed between the bones of the fingers and between the fingers and 
the bones of the fore-arm, contract and move the bones, which are jointed. The tops of the fingers 
are bent on the palm, and the thumb is closed on them, and this continues as long as the contraction 
permits. All the apparatus for long-continued clasping is present in the Gorilla, and there are 
nearly the same kinds of muscles employed as in man. There are, however, some differences, 
to one of which it is necessary now to allude. The thumb, for instance, of the Gorilla is of great 
importance in grasping, but it has not to perform such complicated movements in other things as 
that of man. In man its movements are most wonderful, and by using one muscle after the other 
which belongs to it, it can be moved so as to describe a circle with its tip. This is done in the action 
of “ twiddling/* but also in many others where the will hardly influences the muscle, and where the 
thumb may be said to be moved unconsciously. Gorillas in their quietest and most reflective 
moods cannot indulge in the sober practice of twiddling, for an important twiddling muscle is 
absent in them. But it is no great loss, and perhaps it is a real gain, for this muscle would be in 
the way of rapid clasping, as it rather tends to keep the thumb from the fingers. Whilst the great 
Ape is thus deficient it has a muscle on the other side of the hand which is not possessed by man, 
and whose office appears to be to separate as far as is possible the fourth and fifth fingers (their first 
joints), and by so doing to enlarge the 
grasp of the whole hand. As the hand 
of the Gorilla is at least a third larger 
than that of the averaged-sized man, there 
is of course a corresponding increase in 
the space which can be grasped. The 
muscles are stronger and stouter than in 
us, and therefore the hand is a more 
powerful one. Nevertheless it is incom- 
petent of performing many actions which 
are readily done by a child. 
Having lifted up the arm in the 
act of climbing, and having grasped 
something, the third motion commences, 
the object being to draw up the body 
to the wrist and fingers, which of course remain as fixed points. All the muscles which 
intervene between the fore-arm bones and the spines of the back have to contract and shorten, so 
as to bring the last-named bones towards the fixed point, and they may be divided into three 
groups — those which reach from the arm-bones to the blade-bone, those which connect the blade- 
bone and the back-bone, and those which unite the arm and the back-bone. All contract at once 
and shorten the distance between the body and the arm ; some fix as it were the blade-bone, 
and twist it slightly, placing it in a straight line for the pulling of others ; and the most 
important bend and pull down the elbow. Two muscles may be noticed in particular. One 
which has already been noticed forms the lump on the front of the arm when the wrist is brought 
close to the shoulder, and is called “ biceps/* because it has two heads or points of adhesion to the 
blade-bone, not far from the joint of the arm-bone. The fibres pass over the arm from the blade-bone 
down to one of the bones of the fore-arm, in front of the bend of the elbow, and when they contract 
they tend to bend the elbow and bring the wrist near the shoulder, or the shoulder near the wrist 
when the fingers are fixed or clasping. The biceps of the Gorilla is a vast muscle, but it wants the 
symmetry of that of man, and it does not taper downwards so as to make the arm narrower above the 
elbow. Another muscle is at the back part of the arm, and from having three upper heads or attach- 
ments is called the u triceps.” Two of the heads are attached to the arm-bone, and one to the blade- 
bone, and the lower one is fixed on to the piece of bone of one of the fore-arm bones, on which 
the arm rests when u elbows arc on the table.” Its action is to drag the blade-bone towards that 
bone, and it is assisted in this by a muscle which passes from the spine to the arm-bone, and whose 
office in climbing is to drag the spine towards the arm. Finally, there are numerous muscles which 
