498 
HEMATOLOGY 
90 180 270 360 450 540 630 720 
TIME IN DAYS 
Figure 5. — Prothrombin concentration in bile drained dog. Two-stage 
prothrombin analysis. Arrows indicate events by number: (1) bleeding 
from operative stitch abscess, 210 ml transfusion; (2) vaginal bleeding; 
(3) bleeding from venipuncture site, 130 ml transfusion; (4) bleeding 
from venipuncture site, 110 ml transfusion; (5) some bleeding again, 
160 ml transfusion; and (6) once more, 75 ml transfusion. With bile 
feeding prothrombin concentration increased.^" 
These glimpses from a really rich literature 
must suffice. It would have been interesting to 
give attention to snake venoms and the impor- 
tance of those creatures for this work. I add the 
interesting fact that the hibernation of the 
ground squirrel is a special condition for study- 
ing thrombosis.i'^ With inactivity and sluggish 
circulation, conditions are created which are 
precisely conducive to problems with thrombo- 
sis. Nothing of the sort happens, apparently be- 
cause the blood platelet count drops to low lev- 
els. 
For me, it is self-evident that work with ani- 
mals that have genetically determined deficien- 
cies ought to be conducted on a much more ex- 
tensive scale. Comparative work is likely to be 
fruitful. Surely, the advances made in the 
biochemistry of blood coagulation will now lead 
to extensive developments in the comparative 
aspects, and I have in mind all those animals 
with an adequate plasma supply. The study of 
hemostasis and thrombosis has yielded theoreti- 
cal and practical results, and I presume anyone 
interested would find it a most rewarding in- 
vestment of his time. 
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9. HOGAN, A. G., Muhrer, M. E., and Bogart, R. A 
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