407 



Histology, the new idea does not appear to be very widely accepted. 

 Since blood was first microscopically examined so-called cup-shaped 

 corpuscles have been seen and described. The point at issue is not 

 whether such forms are present in sections, smears or the circulating 

 blood but whether this is the normal type, and whether the more 

 common biconcave disc-shaped corpuscle is "a post-mortem artefact" 

 [Minot] 1). 



As a result of a careful study of sections prepared with various 

 fixing fluids, fresh blood examined as a hanging drop, and the 

 circulating blood in the omentum of the cat, the writer feels convinced 

 that the more normal shape is the ordinarily described biconcave 

 disc; and that the variously modified cup-shaped forms are simply 

 adaptations to exiguous confines or obstructions or currents in the 

 circulating blood, and contraction artefacts in fixed tissues or smear 

 preparations. 



Lewis regards the biconcave discs as resulting from a caving in 

 of the normal cups. He anticipates the objection that immediately 

 suggests itelf; namely, that the depression which makes the cup may 

 itself be due to shrinkage — as I contend. He adds that "the only 

 proof to the contrary is to be had from the circulating blood of a 

 living animal". Such proof he claims to have obtained in the omentum 

 of the guinea-pig where "the flowing blood corpuscles were seen to 

 be flexible bodies, somewhat variable in their proportions, some deeper, 

 some flatter, but all that could be clearly observed were cup-shaped". 



The writer has examined the omentum of an anaesthetised cat 

 for confirmation of the above quotation. Two cats were studied on 

 successive days for a period of an hour and a half each. I am in- 

 debted to Dr. Meloy and to Dr. Hough for assistance in making 

 these experiments and in studying and interpreting the results. The 

 examination was made as suggested by Lewis 2) under an oil immer- 

 sion lens. Under perfectly normal conditions the blood courses very 

 much too rapidly for accurate observations. It is only after the cir- 

 culation has slowed considerably as the result of the cooling of the 

 omentum or of pressure upon the vessel under examination that in- 

 dividual corpuscles can be seen. Even then the corpuscles usually 

 adhere together to form larger or smaller clumps. In such clusters 

 it is only rarely that either typically cup-shaped or biconcave disc- 



1) C. S. Minot, Age, Growth and Death. The Knickerbocker 

 Press, 1908, foot-note p. 76. 



2) Lewis-Stöhr's Text Book of Histology, Philadelphia 1906, p. 142. 



