1888.] Messrs Haycraft & Carlier on Morphological Changes. 223 
and that some become abnormally transparent, as if breaking down ; 
but they are readily stained by dyes, and these changes occur only 
about half an hour after coagulation. 
It has been advanced as a proof that white blood-corpuscles break 
down on shedding of blood, that the number of corpuscles in 
defibrinated blood is less than in undefibrinated blood. Some 
observers have stated that if blood be examined as soon as shed, 
blood-corpuscles may be seen to break down; this we have failed 
to observe. 
The blood was examined in a protecting covering of vaseline, 
made by smearing a slide and cover glass with a thin layer, and 
placing a drop of blood from a greased finger between them. 
Vaseline has been proved to prevent coagulation of blood for a 
time, so that by this method ample time was given us to examine 
the blood before coagulation occurred. 
With this method about fifty specimens were examined, and at 
intervals the white corpuscles drawn and counted in all cases. 
The coarsely granular corpuscles were seen to undergo some 
change, by which their granules accumulated in the centre of the 
cells, and so their outlines became indistinct, but in no case were 
any of the cells seen to disappear as long as observed (some thirty 
minutes), that is long after coagulation of the blood. The finely 
granular corpuscles behaved in the same manner, with the exception 
that their granules did not run to the centres of the cells. 
From these experiments we draw the following general conclusions 
as regards blood shed from the body ; — 
If weather be warm, amoeboid movement begins after from one 
to ten minutes, depending on the temperature. The movement in 
some cases lasts for hours. In other cases the cells change in from a 
quarter of an hour to two or three hours, becoming pale, indistinct, 
granular masses, with their nuclei still visible, and still capable of 
being easily stained. If the weather be cold, amoeboid movement 
is not discernible, but the other changes go on as above. 
Conclusion . — Solid matter mechanically stimulates the white 
corpuscles of the blood, leading to amoeboid movements if the blood 
be not cooled. In any case some metabolic change, associated with 
formation of fibrin, occurs in the white corpuscles, whereby they are 
led to contribute to the production of fibrin. The stimulus in the 
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