of Edinburgh, Session 1885 - 86 . 
855 
is almost exactly the same as that required for the removal of excess 
of blood corpuscles , viz., — 
14-21 days (Quincke), 
14-21 days ( W orm-Mliller), 
14-26 days (myself). 
This similarity in the results is probably more than a mere coin- 
cidence, and can only he explained by assuming that after loss of 
blood the return to the normal is effected, partly by an increased 
formation, hut mainly through a diminished destruction of blood 
corpuscles ; and the time taken for complete restoration probably 
thus represents approximately the average duration of life of the 
newly-formed red corpuscles. 
But Von Ott further found, that if after withdrawing to § 
of the blood he replaced this quantity with an equal quantity of 
defibrinated or entire blood obtained from another dog, the result 
was not, as might have been expected, that the restoration in the 
number of the animal’s blood corpuscles was from that time com- 
plete ; on the contrary, from the day of injection a gradual fall in 
their number occurred till a minimum was reached on the nine- 
teenth to the twenty-second day, not on the second, as after trans- 
fusion of salt solution or serum, and from that time onward a 
gradual increase in their number took place, reaching the normal two 
to three weeks later. 
If we assume, therefore, that this period of nineteen to twenty -two 
days represented the time taken for the destruction of the injected cor- 
puscles, and there is no reason to assume otherwise, since after the 
injection of simple saline solution the minimum was reached on the 
second or third day, then we must conclude that this period repre- 
sented the duration of life of the injected corpuscles under conditions, 
viz., anaemia, the very reverse of that obtaining after the production 
of an artificial plethora. 
These results may he tabulated in the following order : — 
A. After Transfusion . — Time taken for destruction of blood 
corpuscles : — 
Worm-Miiller, .... 14-21 days. 
Quincke, ..... 14-21 „ 
Myself, 14-26 „ 
