616 
G. H. DREW. 
thin protoplasmic connection, often of remarkable length 
relative to the size of the corpuscles, was either directly 
visible, or was demonstrated by the adhesion of passing 
corpuscles. 
If two agglutinated masses of corpuscles, connected by one 
or more such protoplasmic strands, be kept under observation 
for several hours, it will be seen that the strands slowly 
thicken. Corpuscles from each end may travel up a strand 
and appear to become merged in it, as do also any fi’ee cor- 
puscles which may have adhered to it. The corpuscles at 
each end also send out pseudopodia along the strand, and 
may be drawn up into it as it thickens. 
During this process the strand contracts, increasing pro- 
portionately in breadth. The force of this contraction is 
often sufficient to draw together the two neighbouring fibres 
of cotton to which the corpuscles have adhered, and by this 
means the two original masses of agglutinated corpuscles 
may finally be fused into one. 
This phenomenon was studied as far as possible in life by 
making small incised wounds in the foot when under water, 
fixing after varying intervals, and sectionising. Unfortu- 
nately the extremely delicate protoplasmic strands, formed 
between adjacent masses of corpuscles in the earliest stages 
of agglutination, did not withstand the fixing and embedding 
process, but sections of a wound, that had been left for from 
one to two hours before fixation, showed agglutinated masses 
of leucocytes on the edges of the wound, with connecting 
bands running in all directions, thus forming a plug which 
would at least prevent the escape of corpuscles through the 
wound, and probably much hinder the escape of the plasma. 
Sections of wounds a few hours older show'ed the wound 
completely blocked by the agglutinated corpuscles. Sections 
of still older wounds showed that the process of healing in 
many ways resembled that in Mammalia. The agglutinated 
masses of corpuscles soon become more or less structureless, 
and much resemble a mass of fibrin. This is then invaded 
by other corpuscles which have a phagocytic action, and 
