596 



that the existence of which is here assumed, the torn edges would 

 immediately tend to come together again after rupture, and would 

 then show no indication of the breach of continuity. A similar ex- 

 planation may be given of the fact that a corpuscle may sometimes 

 be cut in two, as when a needle is drawn sharply across a preparation 

 of newt's blood upon a glass slide, without the coloured contents 

 escaping from the two separated parts; in this case the pressure of 

 the needle point has at the same time that it severed the corpuscle 

 brought together the opposite edges of the cut pellicle, and thus pre- 

 vented the escape of the contents" ^). 



The considerations which were thus set forth as long ago as 

 1892—93, which corroborated and extended the conclusions arrived 

 at by NoRRis in 1869, have in no way lost in strength during the 

 twelve years which have intervened but have obtained strong corro- 

 boration in the work of L. Hermann 2), Albrecht^) and Koeppe^). 

 They point to the fact that the envelope of the erythrocyte contains 

 a considerable proportion of material physically resembling fat and 

 actually consisting chiefly of lecithin and Cholesterin, mixed with the 

 nucleoproteids which are characteristic of protoplasm. 



It was at that time assumed by the author, and the same as- 

 sumption has been made by other writers who have taken a similar 

 view of erythrocyte structure, that the membrane is homogeneous and 

 contains these protoplasmic constituents uniformly intermingled or 

 combined. But various observations, such as the eifect of heat, the 

 result of cutting the corpuscles and especially the phenomenon of 

 rouleau formation, show that this greasy, myelinic material is accumu- 

 lated at the surface of the membrane rather then distributed uniformly 

 through its substance ^). At least it appears that this conclusion must 



1) This experiment has been adduced as affording the strongest 

 evidence on behalf of the stroma theory, since it is argued that the 

 corpuscle must be homogeneous to allow of such severance into parts 

 without the escape of haemoglobin. But if we assume the surface pellicle 

 of the corpuscle to be of a greasy nature (a condition to which other 

 considerations point) not only does the objection which it appeared to 

 oifer fall to the ground but the fact becomes itself a strong argument 

 in favour of the vesicular theory. 



2) Pflügbr's Arch., 1899, Bd. 74, p. 1(34. 



3) Verhandl. d. Deutschen Pathol. Gesellsch., 1902/04. 



4) Pflüger's Arch., 1903, Bd. 99, p. 33. 



5) Hexsen showed that each separated portion of an erythrocj'te 

 was enclosed by a pellicle similar to that of the undivided corpuscle. 

 Zeitschr. f. wissensch. Zool., Bd. 11, 1862. 



