412 



various fixing reagents one finds abundant cup-shaped corpuscles, more 

 or less regular, many irregular forms, and a few irregular discs. 

 Could one reasonably expect anything else under the conditions? I 

 contend that by virtue of the peculiar structure the disc-shaped cor- 

 puscle most naturally take a cup or saucer shape when contracting. 

 Contraction is probably unequal in centre and rim. 



In a section of the inferior vena cava of the cat, filled with blood 

 the great majority of the corpuscles are cup -shaped. Some irregular 

 shapes are seen as also a few biconcave discs. This confirms Lewis' 

 finding that in Zenker fixed tissue cup-shaped forms abound. But I 

 do not agree with Lewis in supposing them to represent well-pre- 

 served normal shapes. The section shows a considerable coagulum; 

 and I interpret the shape of the corpuscles as the result of the coagu- 

 lation and contraction of the protoplasm under the influence of the 

 Zenker's fluid. 



On the other hand, in a Zenker fixed preparation of a 2.5 cm 

 pig embryo the vast majority of the red corpuscles are clearly bicon- 

 cave discs (it is remarkable how many are seen on edge in this pre- 

 paration); among them are seen some irregular forms and a consi- 

 derable number of nucleated forms. This finding seems to oppose 

 Minot's ^) conclusion that as the corpuscles lose their nuclei they con- 

 tract and become cup-shaped. Again in a Zenker preparation of the 

 placenta certain portions contain mostly disc-shaped corpuscles both 

 in the villi and in the intervillous spaces (here most seem to present 

 their flat sides); other portions contain mostly irregular and cup- 

 shaped forms. In another Zenker preparation (of the Gasserian gan- 

 glion), the majority of the blood corpuscles are cup-shaped. 



As a result of my examination of the omentum of the cat under 

 ether, hanging-drop preparations of human blood, and sections of 

 tissue from several domestic animals I can confirm Weidenreich and 

 Lewis in their conclusion that mammalian blood contains "bell"- or 

 "cup-shaped" red corpuscles; but I am compelled to take issue with 

 them in their opinion that this represents the normal form, and that 

 the biconcave discs are artefacts. I believe that my findings justify 

 the interpretation of all variations in normal blood from biconcave 

 disc-shapes as the result of the operation of extrinsic physical factors, 

 necessitating adjustment to narrow confines or obstacles or currents, 

 or as the result of contact with viscid bodies (other corpuscles) and 

 of unequal contraction. 



1) loc. cit. p. 79. 



