26 
TRANSLATIONS. 
On the OssiricaTion of the PrrmorpIAL CARTILAGE. 
By A. Baur, of Tubingen. 
(Abstracted from Miiller’s ‘ Archiv,’ 1857, No. 4, p. 347.) 
A mricroscopicaL analysis of the changes which take place 
in the ossification of cartilage has two questions to resolve : 
First, in what way does the peculiar structure of osseous 
substance arise from the so widely different structure of car- 
tilage? and, secondly, im this process, im what relation do 
the elements of the cartilage stand towards those of the 
bone? The latter question especially, since it has become 
known that bone may be formed without any pre-existing 
cartilage, has acquired redoubled interest. 
The origin of all osseous substance, not previously car- 
tilage, must be referred to the ossification of a blastema, 
which, according to most observers, is to be regarded as of 
the same nature as that of connective tissue; it consists, 
that is to say, of a matrix as yet indistinctly fibrillated, in 
which are scattered simple rounded cells, identical with the 
primary formative cells of connective tissue—the future con- 
nective tissue corpuscles. It is easily perceived that the 
ossification of this blastema is effected simply by the deposi- 
tion of calcareous matter in its intercellular substance, owing 
to which it gradually, and without any distinct lne of limi- 
tation, assumes the character of the osseous basal substance, 
whilst the cells shoot out into the irregular bone-corpuscles. 
In this case, it is certain that no intermediation of cartilagi- 
nous elements takes place ; nor can any indication of a pre- 
vious opacity dependent upon calcareous particles be re- 
marked. The process, therefore, can only be described as a 
direct ossification of the connective tissue. 
The process of ossification in cartilage is more complex. 
In this case, a simple transformation of the substance does 
not take place, but simultaneously with it a total change of 
structure, in consequence of which it becomes difficult to 
trace the histological alterations. The most favorable objects 
for examination are, perhaps, thin transverse sections made 
in various directions through the ossifying border of the dia- 
physis of a foetal long-bone, in as fresh a condition as possible. 
