100 
Dr. BealEj on the so-called 
Of the Formation of the Matrix. 
In the fresh cartilage of the frog the actual conversion of 
the germinal matter into formed material may be studied. 
In the preparation passed round (Prep. 4)^ magnified 700 dia- 
meters, numerous oval or spherical masses of a granular ap- 
pearance will be noticed,, but amongst them many of a half- 
moon shape may be observed, and others varying very much 
in shape, and with so ragged and irregular an outline that no 
one would be disposed to call them cells, or would maintain 
that they possessed a cell-wall. (Figs. 2, 3, 4, 5, 6, 7, 8.) At 
the edge of the specimen, where it is exceedingly thin, some of 
these angular masses, composed of granular matter, with the 
central part deeply coloured with carmine (nucleus), can be 
seen to shade uninterruptedly into the matrix. The granular, 
ragged edges gradually pass into, and are continuous with 
the clear, transparent matrix. Not only so, but in some of 
the oval masses, the formation of the clear, transparent matrix 
is seen to commence as a separate point in the granular matter 
itself, as well as to proceed upon its surface. In other parts 
of the specimen nothing but what would be termed the 
nucleus remains. It seems to be imbedded in the matrix of 
the cartilage, so that the whole of the outer part of the '^cell' 
has been transformed into this structure (matrix, intercellular 
substance), and the change has proceeded until of the ger- 
minal matter only a very small portion remained unchanged. 
This would soon die, and almost entirely disappear. A small 
space occupied by a few granules would remain in the sub- 
stance of the cartilage, and this is all that would remain to 
mark the position of a cartilage -cell. 
If I have interpreted these phenomena correctly, the history 
of the life of cartilage and allied structures is very simple, and 
easily understood. Masses of germinal matter appropriate 
pabulum, and having thereby increased in size, divide and 
subdivide, while those portions which are oldest and at the 
outer part of each mass gradually cease to manifest their 
active powers, and become resolved into soft-formed material, 
which gradually accumulates and undergoes condensation. 
The formation of the matrix proceeds more and more slowly 
as the tissue advances in age, because the impediment offered 
to the access of pabulum to the germinal matter must become 
greater as the formed material around it increases in amount 
and undergoes condensation. 
It seems to me, therefore, that the vital changes occurring 
