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40 AXATOMY, . — —
(c) Sharpey's or Perforating Fibres.—Besides the three systems
of lamellte which form for the most part all the intercellular substance
of bone, there is found in many instances a well-defined system of fibres
known as Sharpey's fibres (see Fig. 6). These pass through or pene-
trate the lamellffi in a perpendicular or oblique direction, appearing to
dowel or bind the parts together. Many pass from the periosteum
especially is this marked in the external table of the cranial bones
while others seem to have their origin from some of the intermediate
Fig. 6.
LamellK torn off from a Decalcified Human Parietal Bone at some depth from the surface: n. Ions;
lamellse ; b, h, thiclver part, where several lanielUe are siiperpos' d ; c, r, perforating fibres : the tilirils
wliich compose them are not sliown in the figure. j\perfures through which perforating fibres liad
passed are seen, especially in the lower part, a, a, of I he figure (magnitude as seen under a power of
200, but not drawn to a scale).
lamellse of the interstitial or circumferential systems, though it is more
probable they had their origin from the periosteum when that mem-
brane Avas in close contact with the lamella from which their fibres start.
These fibres are not found in the Haversian lamellae. If a lamella is
torn away from a decalcified bone, these fibres can be seen attached to
the under surface of the removed portion, the apertures being visible in
the remaining l^one from which the fibres have been drawn. They
are suppo.'^ed to be o.'*sified bundles of white fibrous tissue originally
belonging to the inner layer of the periosteum.^
Occasionally the.se fibres do not ossify, and as they shrink or are
drawn out in removing the periosteum, perforations will be found lead-
ing into the bone. It is by means of these perforating fibres that tendons
and ligaments obtain such firm hold upon bones, their number being
increased at the points of such attachments.^
e, Fig.
' Perfriratinir fibres (r, Pi) exist almndantly in the crnsta petrosa or cementum
of the teeth iSiiarpey). H. Miiller has shown that some are of the nature of elastic
tissue (Qnain's Amilomii).
' The filtre-liiindles of the tendon are continued into the bone as perforating fil)res.
Some of the l)uiidles of white fdires of the periosteum may also |)ass into the bone as
perforating tibres, and the same is the case with elastic fibres (Qnain's Anatomy).
(c) Sharpey's or Perforating Fibres.—Besides the three systems
of lamellte which form for the most part all the intercellular substance
of bone, there is found in many instances a well-defined system of fibres
known as Sharpey's fibres (see Fig. 6). These pass through or pene-
trate the lamellffi in a perpendicular or oblique direction, appearing to
dowel or bind the parts together. Many pass from the periosteum
especially is this marked in the external table of the cranial bones
while others seem to have their origin from some of the intermediate
Fig. 6.
LamellK torn off from a Decalcified Human Parietal Bone at some depth from the surface: n. Ions;
lamellse ; b, h, thiclver part, where several lanielUe are siiperpos' d ; c, r, perforating fibres : the tilirils
wliich compose them are not sliown in the figure. j\perfures through which perforating fibres liad
passed are seen, especially in the lower part, a, a, of I he figure (magnitude as seen under a power of
200, but not drawn to a scale).
lamellse of the interstitial or circumferential systems, though it is more
probable they had their origin from the periosteum when that mem-
brane Avas in close contact with the lamella from which their fibres start.
These fibres are not found in the Haversian lamellae. If a lamella is
torn away from a decalcified bone, these fibres can be seen attached to
the under surface of the removed portion, the apertures being visible in
the remaining l^one from which the fibres have been drawn. They
are suppo.'^ed to be o.'*sified bundles of white fibrous tissue originally
belonging to the inner layer of the periosteum.^
Occasionally the.se fibres do not ossify, and as they shrink or are
drawn out in removing the periosteum, perforations will be found lead-
ing into the bone. It is by means of these perforating fibres that tendons
and ligaments obtain such firm hold upon bones, their number being
increased at the points of such attachments.^
e, Fig.
' Perfriratinir fibres (r, Pi) exist almndantly in the crnsta petrosa or cementum
of the teeth iSiiarpey). H. Miiller has shown that some are of the nature of elastic
tissue (Qnain's Amilomii).
' The filtre-liiindles of the tendon are continued into the bone as perforating fil)res.
Some of the l)uiidles of white fdires of the periosteum may also |)ass into the bone as
perforating tibres, and the same is the case with elastic fibres (Qnain's Anatomy).
