1)r. Beale, on the Germinal Matter of the Blood, 59 
force, the process would continue until a firm '^clot^^ re- 
sulted. 
The formation of fibrin, therefore, it seems to me, is to be 
regarded as the result of a vital process. I consider fibrin 
as formed material,^^ and hold that living germinal matter 
becomes fibrin. 
Fibrin is produced by the white blood-corpuscles, chyle, 
and lymph-corpuscles, by corpuscles of the same essential 
nature in the intercellular fluid, by some the corpuscles in the 
so-called exudations; germinal matter generally, in dying 
under certain circumstances, gives rise to the production of 
an elastic fibrinous material which is closely allied to the 
fibrin of the blood. Even in vegetable cells there is a sub- 
stance closely allied to fibrin, and spontaneous coagulation 
is a phenomenon that usually follows the death of living or 
germinal matter. 
Now, 1 have already shown that the living germinal matter, 
so long as it possesses the power of moving and forming out- 
growths and protrusions, is very transparent and refracts 
very slightly, but when this dies, a firm, more or less elastic 
material results which resists the action of acetic acid, and 
refracts light in a much greater degree, results These charac- 
ters have, it seems to me, led observers to infer too hastily that 
the matter which extends from the masses of living or ger- 
minal matter, as for example in white fibrous tissue, should 
be called elastic tissue. There is a material resulting from 
the death of particles of germinal matter under certain 
circumstances, which refracts the light highly, which resists 
the action of acetic acid, potash, and soda, — but it by no 
means follows that this in all cases is elastic tissue.^^ 
Cause of the granular appearance of the white blood-corpuscle. 
In the white blood- corpuscles the granular appearance is 
caused by the presence of a number of spherical or oval 
particles which refract in a greater degree than the trans- 
parent material of which the greater part of the corpuscle is 
composed. These particles are more numerous in old white 
blood- corpuscles than in others ; and in the youngest they do 
not exist at all. They increase in number afer death. I 
believe that the matter of which these granules are composed 
is already dead, is, in fact, fibrin. (See PI. IX, figs. 3 and 4.) 
If the fibrinous mass from Gruinea-pig^s blood, which coagu- 
lates very rapidly, be examined under a very high power, it 
presents a similar appearance, there being no distinct 
''threads'' visible. (See fig. 7.) 
