The author discusses the absence of the ligamentum capitis femoris (LCF) in chimpanzees,
orangutans and some other mammals. Richard Owen expressed an interesting
thought: «There can be little doubt that the absence of the ligamentum teres is
one cause of the greater vacillation observed in the Orang Utan, when it
attempts progression on the hinder legs, than in other Quadrumana.»
XXXIX.
On the Osteology of the Chimpanzee and Orang Utan.
By
RICHARD OWEN, Esq., F.R.S. & Z.S.,
Assistant
Conservator of the Museum of the Royal College of Surgeons in London.
Quote pp. 351-352
1. Of the Osteology of the adult Chimpanzee.
The femur of the
Chimpanzee is slightly bent in the anterior direction, as in the human subject:
the neck of the bone has the same comparative length, but stands out more
obliquely to the shaft. The whole of the body of the bone is flatter or more
compressed from before backwards. An error which has crept into the excellent
and laborious work on Comparative Anatomy which the lamented death of the
celebrated Meckel has left unfinished, requires here to be noticed, as it
attributes a community of structure to the two species of Orang in a part which
affords one of the best-marked differences. The head of the femur, which
presents a smooth unbroken surface in the Orang, is marked with the pit for the
attachment of the ligamentum teres as well in the adult as in the young
Chimpanzee, in which I have ascertained the existence of that ligament in a
dissection of a recent specimen. Meckel describes the absence of the ligamentum
teres in the Pongo as well as in the Orang, and this is the case; but it is
only another of the many coincidences of structure which prove the identity of
the two animals. This peculiarity of the hip-joint appears to relate to the
disproportionate shortness of the legs in Simia Satyrus; but the deterioration
which they consequently suffer, as means of support, is compensated by the
advantages which they gain as instruments of prehension, their extent and
variety of motion being increased by the removal of a ligament that acts as an
impediment to both in the animals which possess it.
Quote pp. 365-366
§ 3. Osteology of the Orang Utan.
The femur has a straight shaft, but
differs from the human chiefly in having no depression on the head for a
ligamentum teres (1). The neck is shorter and forms a more obtuse angle with
the shaft of the bone, and there is not any linea aspera at the posterior
part; the inner condyle also is not produced beyond the external, and the axis
of the femur is consequently the same with that of the tibia, - a circumstance
which may also be observed in Simia Troglodytes. In both species the natural
position of the femur is evidently a state of inflection upon the pelvis; the
head must be partially displaced from the acetabulum in order to draw back the
femur to a line parallel with that of the spine, as may be seen by comparing
the figure of the Chimpanzee (Plate XLVIII.) with that of the Orang (Plate
XLIX.). The angle which the femur forms with the trunk is more obtuse in the
Chimpanzee than in the Orang, in which the arms are better organized as
vicarious instruments of support.
1) In three recent
specimens of Simia Satyrus I have found the ligamentum teres deficient in both
the hip joints. This singular circumstance in the organization of the Orang
Utan is not noticed in the Manuals of Comparative Anatomy of Blumenbach or
Cuvier, although it has been recorded by Camper in his Treatise on the Orang.
(See Œuvres, tom. i. p. 132.) It appears also to have been overlooked in the
dissection of the Orang detailed by Dr. Jeffries (Boston Journal of Philosophy,
vol. ii. p. 570; Philosophical Magazine, vol. lxvii. p. 186.), unless, from the
inference which he draws, the hip-joint of his specimen really presented this
remarkable exception to the general structure. He says: "The articulation
of the femur with the acetabulum is almost exactly like Man's; the neck of the
bone forms about the same angle. In quadrupeds this forms a distinguishing
characteristic, being in them nearly a right angle: the inspection of this
joint is alone sufficient to satisfy the naturalist of at least the facility,
if not the natural disposition, of the Satyrus to walk erect"! The
skeleton is doubtless still preserved, and it would be worth while to make a
re-examination of the head of the femur to ascertain the presence or otherwise
of the depression for the ligamentum teres.
In all the other Quadrumana which
I have examined the ligamentum teres is present, but in none of them are the
legs so disproportionately short as in the Orang; the deficiency of the
ligament doubtless, therefore, bears a relation to this circumstance, and a
greater flexibility of the hip-joint, especially of rotation inward, is the result.
In the Unau (Bradypus didactylus, Linn.) and Ai (Brad. tridactylus, Linn.),
with hinder limbs of similar proportions to those of the Orang, and habits
still more strictly arboreal, a similar extent of motion is allowed to the leg
by the absence of a restraining ligament in the hip-joint.
In the Elephant and Megatherium
the deficiency of the ligamentum teres would seem to relate to the position of
the acetabulum with reference to the head of the femur, the socket resting upon
the ball, and not receiving it obliquely sideways, as in most other quadrupeds.
In the Manis didactyla, in the
Seal, and in the Walrus, the ligamentum teres is wanting. Rudolphi and Meckel
have noticed a similar simplicity in the structure of the hip-joint in the
Ornithorhynchus paradoxus, and I have also found that the same structure
obtains in the Echidna Hystrix and Ech. setosa. There can be little doubt that
the absence of the ligamentum teres is one cause of the greater vacillation
observed in the Orang Utan, when it attempts progression on the hinder legs,
than in other Quadrumana. In Dr. Abel's account of the capture of a very large
Sumatran Orang, it is observed, "His motion on the ground was plainly not
his natural mode of progression, for even when assisted by his hands or a
stick, it was slow and vacillating; it was necessary to see him amongst trees
in order to estimate his agility and strength." In Audebert's Histoire des
Singes, p. 18, is a note on the progressive motion of the Orangs, which closely
accords with the structure above mentioned; it is as follows: "Un
naturaliste voyageur, M. Labillardière, qui a vu de ces animaux, m'a assuré que
lorsqu'ils marchent leurs jambes de derrière sont pliées en sorte que ce sont
les jambes de devants qui cheminent." And this account of the use he makes
of his long arms in progression along the ground is confirmed by the
observations of M. Fred. Cuvier, who has given some valuable observations on
the habits of a living Orang Utan in the sixteenth volume of the Annales du
Muséum'. He observes: Cet Orang-Outang étoit entièrement conformé pour grimper
et pour faire son habitation des arbres. En effet, autant il grimpoit avec
facilité, autant il marchoit péniblement: lorsqu'il vouloit monter à un arbre
il en empoignoit le tronc et les branches avec ses mains et avec ses pieds, et
il ne se servoit que de ses bras, et point de ses cuisses comme nous le faisons
dans ce cas. Il passoit facilement d'un arbre à un autre lorsque les branches
de ces arbres se touchoient, de sorte que dans une forêt un peu épaisse il n'y
auroit eu aucune raison pour que cet animal descendit jamais à terre, où il
marchoit difficilement. En général tous ces mouvemens avoient de la lenteur;
mais ils sembloient être pénibles lorsqu'il vouloit se transporter sur terre
d'un lieu dans un autre d'abord il appuyoit ses deux mains fermées sur le sol,
se soulevoit sur ses long bras, et portoit son train de derrière en avant en
faisant passer ses pieds entre ses bras et en les portant au delà des mains;
ensuite appuyé sur son train de derrière il avançoit la partie superieure de
son corps, s'appuyoit de nouveau sur ses poignets, se soulevoit et recommençoit
à porter en avant son train de derrière comme nous l'avons dit d'abord."
In three living specimens of the immature Orang
I have witnessed the same debility of the hinder extremities as instruments of
support. If, however, the peculiar construction of the hip-joint add to the
difficulty of progression in the erect posture, arising from a form of the
pelvis and inferior extremities common to the Orang with other Simia, it
doubtless facilitates his favourite mode of travelling among the branches of
his native forests, by allowing a greater variety and extent of motion to the
lower extremities, and by thus combining, as it were, the peculiar freedom of
the shoulder-joint with the hand-like form of the foot.
Quote p. 368
§ 4. Summary Comparison of the Chimpanzee and Orang Utan with each other
and with Man.
…
21. In the presence of a ligamentum teres, and consequent depression in the head of the femur.
External links
Owen R. On the osteology of the Chimpanzee and Orang. Transactions of the
Zoological Society of London. Vol. I. London, 1835:343-379. [books.google]
Authors & Affiliations
Richard Owen (1804-1892) was an English biologist, comparative anatomist and palaeontologist professor at the Royal College. [wikipedia.org]
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| The young Richard Owen Author: Ballista; original in the wikimedia.org collection (CC0 – Public Domain, no changes) |
Keywords
ligamentum capitis femoris, ligamentum teres, ligament
of head of femur, animals, chimpanzee, orangutan,
walking anatomy
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