PHYSIOLOGY UP LAMELLIBRANCH BLOOD-CORPUSCLES. 617 
they are accompanied by connective-tissue corpuscles with 
elongated nuclei, which form connective tissue. At the same 
time, in the case of small incised wounds of the foot, the cut 
muscle-fibres grow across, and the surface epithelium joins 
up over the surface of the wound, so that after the lapse of 
about three weeks the site of the wound may be almost 
indistinguishable in sections. 
I consider that the process as observed in the plasticine 
cell is probably identical with that in Nature. When a wound 
is made, the tissues along the immediate margins of the 
wound have their vitality impaired, and though perhaps not 
dead, are at least in an abnormal state. As the blood 
escapes, the corpuscles impinge on these tissues and agglu- 
tinate, and connecting strands of protoplasm may be formed 
between masses of corpuscles on opposite sides of the wound, 
in the same tnanner as that described when the blood is 
drawn through cotton-wool. The subsequent thickening and 
contraction of these bands of protoplasm would tend to draw 
the edges of the wound together, and cause complete fusion 
between the neighbouring masses of agglutinated corpuscles. 
It is obvious that some change takes place in the corpuscles 
of blood which has been withdrawn from the animal, which 
confers on them the power of agglutination. Of the nature 
of this change I have no evidence. Arguing by analogy, it 
seems possible that it is due to the liberation of some enzyme 
from the corpuscle. There is no visible change in the con- 
tents of the cells after agglutination, and stained preparations 
show that both the large and small eosinophil granules are 
still present. 
The effect of exposure to air, as a predisposing cause of 
agglutination, may be eliminated by the fact that a small 
wound, made under water, soon becomes plugged with agglu- 
tinated corpuscles, and also by the fact that agglutination 
occurs when the blood has been collected under water in a 
narrow pipette already partially full of sea-water. This does 
not dispose of the action of dissolved air, but it is reasonable 
to assume that the blood during its passage through the gills 
