Dr. BealEj on the Red Blood-corpuscle. 
41 
than while the corpuscles were circulating. It therefore grows, 
and divides,, and subdivides. In the case of frog's blood ex- 
travasated into the tissues of the living body, T have seen 
appearances which have led me to infer, that spherical granu- 
lar cells have been produced from the germinal matter of the 
red corpuscles. In clots in vessels of mammalia, granular 
cells are often found in considerable number. They result 
from the white corpuscles, and from what may be called 
young red corpuscles. Just as the germinal matter of an or- 
dinary cell may take up the softened, formed material which 
surrounds it, so it is possible that the germinal matter of 
a frog's blood-corpuscle may increase by taking up the 
coloured material — may, in fact, live at its expense. This is 
one way in which the colouring matter of stagnant blood may 
be removed. 
In the fully formed frog's blood- corpuscle the germinal 
matter seems to cease abruptly, rather than gradually to pass 
into the formed material ; but in young cells a gradual tran- 
sition may sometimes be observed. In young corpuscles 
(mammals as well as reptiles) it would seem that the coloured 
matter is deposited amongst the particles of germinal matter, 
which accords with what occursinsome coloured vegetable cells, 
so that the coloured formed material maybe removed in the form 
of solution, leaving the colourless living germinal matter behind; 
or the coloured material may collect in the form of globules, 
which may remain imbedded amongst the germinal matter, or 
pass through it into the surrounding fluid. Blood-corpuscles of 
this kind are capable of growth, and doubtless also of multipli- 
cation. The crystallization of many entire blood- corpuscles 
is, however, opposed to the view that such is the constitution 
of the mammalian red blood-corpuscle at all ages. And 
although certain phenomena observed to occur in the outer 
coloured portion of the red blood-corpuscle might be advanced 
in favour of the view that this may have living, germinal, or 
protoplasmic matter diffused through it, I cannot but think 
that a careful consideration of the facts alluded to in the ear- 
lier part of this paper render such a conclusion untenable. 
Of the nature and mode of formation of the mammalian red 
blood-corpuscle. 
As is well known, in the blood of the embryo, and in 
young animals, corpuscles possessing a so-called granular 
nucleus, surrounded by a smooth external portion, are com- 
mon enough ; but in the blood of the adult are numerous cor- 
