p. L. BLACKSHEAR AND R. J. FORSTROM 
539 
12. BuGLiARELLO, G., Kapur, C, and Hsiao, G.: The 
Profile Viscosity and Other Characteristics of 
Blood Plow in a Non-Uniform Shear Field, Proc. 
4th Int. Rheology Conf. (edited by Copley, A. L.), 
4:351, 1964. 
13. Brenner, H., and Bungay, P. M.: Rigid-Particle 
and Liquid-Droplet Models of Red Cell Motion in 
Capillary Tubes, Fed. Proc, 30:1565, 1971. 
14. FORSTROM, R. J., Blackshear, p. L., Keshaviah, 
P., and Dorman, F. D. : Fluid Dynamic Lysis of 
Red Cells, Advances in Bioengineering, Chem. Eng. 
Progress Symp. Series, 67:69, 1971. 
15. Rand, R. P., and Burton, A. C: Area and Volume 
Changes in Hemolysis of Single Erythrocytes, J. 
Cell. Comp. Physiol. 61:245, 1963. 
16. Leonard, E. F., and Friedman, L. : Thrombogenesis 
on Artificial Surfaces: A Flow Reactor Problem, 
Chem. Eng. Prog. Symp. Ser., 66:59, 1970. 
17. Petschek, H. E., and Madras, P. N. : Thrombus 
Formation on Artificial Surfaces. Proc. Artif. 
Heart Program Conf., (edited by Hegyeli, R. J.) 
Washington, D.C.: U.S. Govt. Printing Office, p. 
271, 1969. 
18. Goldsmith, H. L.: Red Cell Motions and Wall In- 
teractions in Tube Flow. Fed. Proc, 30:1578, 1971. 
19. Blackshear, P. L., Forstrom, R. J., Dorman, F. D., 
and Voss, G. O.: Effect of Flow on Cells Near 
Walls, Fed. Proc 30:1600, 1971. 
DISCUSSION 
Sidney Cassin, University of Florida, 
Gainesville, Fla. : Is there a relationship be- 
tween the size of the cell in the other species 
and the age of the animal? In other words, are 
the goat's red cell forms in fetal blood much 
larger than in the mature goat? 
Dr. Blackshear : I think I'm the wrong per- 
son. We didn't study this in other species. Does 
anyone know if fetal goat blood is larger? I 
would expect it would be. What do you think, 
Bert? 
Bert K. Kusserow, University of Vermont, 
Burlington, Vermont : I don't know about goats, 
but in the dog, the younger red cell forms seem 
to be slightly larger. The possibility may exist, 
too, as the cell moves out from the marrow 
and is released in the blood stream, that there 
may be a slight decrease in size. This holds true 
for the dog. I am not familiar with goat's fetal 
blood. 
Dr. Cassin : Why were precautions taken to 
have a controlled environment and fixed plasma 
in all of the experiments? 
Dr. Blackshear : Because it is a very sensi- 
tive thing. 
John T. Reeves, University of Kentucky, 
Lexington, Ky. : How does the position of the 
tube relate to this ? I presume this was in fairly 
large diameter vessels, but I wonder as you get 
to approach the capillary side, how this will in- 
fluence your analysis. 
Dr. Blackshear: Well, for the larger size 
vessels, it's pretty clear that the smaller, more 
rigid cells should come closer to the wall. In 
the work that's been done on the capillary flow, 
the less deformable the cell, the closer the cell 
goes to the wall. Hence, one would guess that 
capillary resistance, all things being equal, 
should be higher in the goat cell than it is in the 
elephant cell, simply because it would resist de- 
formation. I should add that one of the con- 
sequences of this shear stress analysis is to 
conclude that, of the species studied, the mem- 
brane tension at lysis is the same for all mam- 
malian species. We had never been able to dem- 
onstrate this before now. 
