OSSEOUS TISSUE. 
the embryo may be considered the element of 
the lamine. 
Again, the intercellular tissue found in the 
embryo forms the medium of connection be- 
tween the cartilage cells or corpuscles, as 
theyare called, between the primary tubes, where 
bone is developing, and lastly, becomes the bond 
‘of union between the Haversian systems. 
The foregoing description applies to the 
growth of the shaft of a long bone in the carti- 
‘lage connecting it with the epiphysis. 
The laws regulating the growth of the epiphysis 
in the cartilage which unites it to the shaft of 
‘the bone are but a slight modification of those 
which regulate the growth of the shaft. The 
cartilage corpuscles, however, here form sinall 
rounded groups, and ossification proceeds in 
the intercellular tissue around them, and the 
groups themselves eventually form a cavity, by 
which means the spongy head of the bone is 
formed. The flat bones are developed much 
as the long ones, the thin edges of these being 
sapped with cartilage, which developes its cells, 
and intercellular tissue. 
_ A bone at the time of its development is of 
equal density through the whole diameter at 
the point where ossification is just perfected. 
The arrangement of compact and spongy, as 
seen in the various bones, is an after process 
which takes place gradually, and in relation to 
the individual bones of which the framework of 
the body is composed. 
On considering the process of developement 
of bone, it will be apparent that the arrange- 
ment of cells, intercellular tissue, &c. answers 
the purpose of giving a definite form and 
arrangement for the future nourishment of the 
bone, but that osseous tissue is independent of 
any particular form. Thus intercellular be- 
<omes osseous tissue, as does the tissue of the 
cells. I wish to lay stress upon this point, as 
it bears particularly upon the character of 
certain formations of bone in unnatural 
Situations, or adventitious bone. 
Ossification of permanent cartilage-—The 
cartilages of the larynx at an advanced age are 
‘liable to become ossified, and in such cases, as 
the formation of osseous tissue goes on but 
slowly, the process may be observed with ease. 
In this case the corpuscles do not develope 
others as in temporary cartilage where increase 
of size is required, but retain their usual 
appearance. While the osseous granules are 
developed in the intercorpuscular tissue, at first 
but few of them are seen, and these spherical 
and isolated; they soon, however, become 
numerous, and unite, thereby forming an osseous 
mass. The intercellular or intercorpuscular 
tissue having advanced in ossification, the cor- 
puscles, or rather their parietes, pass through 
the same process, and by degrees the whole 
cartilage becomes converted into bone. 
The formation of the individual granules is 
more readily observed in these cartilages than 
in any other situation. This form of ossifi- 
cation establishes an interesting and explanatory 
link of connection between bone and the various 
osseous plates we find in abnormal situations. 
For in the latter the spherical granules appear, 
857 
and these, at first few and isolated, and lying 
amongst the fibres of the tissue, rapidly in- 
crease in number;.unite, and form an osseous 
mass. reeet 
Osseous plates occur in various soft tissues 
as the result of deranged action, where in the 
healthy condition of the part they are not found. 
Thus we have osseous plates formed in the coats 
of arteries, in. the pleura, in the diaphragm ; 
also osseous masses in the uterus; and some- 
times in the muscular tissue and in the pla- 
centa. These plates are all formed in the same 
manner, namely, by the developement of 
minute spherical osseous granules, which form 
into a mass, the shape of which is modified by 
the form of the tissue in which the develope- 
ment occurs. 
I have examined many of thése formations 
and find them to be composed of true osseous 
tissue, but not true bone ; for they have not the 
definite Haversian systems, which, formed of 
osseous tissue, constitute bone. But they have 
cavities scattered through them ; these, however, 
have no definite shape, but assume all kinds of 
irregular forms, and though they are no doubt 
necessary to the vitality of the mass, yet their 
action cannot be very perfect. Spicule of 
osseous matter are sometimes met with in 
cancerous tumours, but here it is very rare to 
find an Haversian system. The osseous plates 
found in the dura mater are, however, true 
bone, and are developed like the flat bones. 
I am decidedly of opinion that these masses 
are endowed with vitality, and are not mere 
concretions as some have regarded them, 
though this vitality is of a low degree. 
Formation of osseous tissue in union of frac- 
tured bones.—Supposing the subject in which 
the fractures occur to be young, cartilage 
similar in every respect to temporary cartilage 
is produced between the fractured extremities 
of the injured bone. In the centre of this 
ossification commences, the process being 
somewhat similar to ossification of permanent 
cartilage, or holding an intermediate place 
between that process and the ossification of 
epiphyses. 
The corpuscles here increase in size but not 
in number. The ossification commences in 
the intercellular tissue, and proceeds: to the 
parietes of the cells, thus forming areole of 
bone. 
The action may also commence in the carti- 
lage in contact with the fractured surface. 
This I believe to be the process by which repa- 
ration is effected in all cases where union of 
fractured bones takes place, but my experi- 
ments have been confined to young animals. 
I have examined various cases where union 
has not been effected in consequence of the 
patient’s advanced age, and the fracture being at 
the neck of the femur or of the shaft of the same 
bone. In these I found no cartilage, and but 
a scanty amount of condensed cellular tissue. 
In this latter, however, traces of an attempt 
at repair may generally be found in the pre- 
sence of osseous matter in granules or granular 
masses. In these there is no arrangement of 
tubes or bone-cells of definite character; indeed 
