ORIGIN OF RED BLOOD-CORPUSCLES. 
331 
The Origin of the Red Blood-Corpuscles. By Professor 
PoucHETj of the Jardin des Plantes^ Paris.^ 
I HAVE paid a good deal of attention lately (since November, 
1877) to the study of the formed elements of the blood and 
their origin. The fact was, as often happens, that several 
histologists were pursuing, both in France and elsewhere, the 
same investigation. 
I propose to give a summary of what seems to me to be 
the actual state of our knowledge on a subject of such 
importance both to physiology and to medicine. 
A sufficiently large part in these studies, which have been 
followed out with vigour in various quarters, has been given 
to the history of that singular phenomenon the coagu- 
lation of the blood. I shall put this subject entirely on one 
side, only wishing to occupy myself here with the formed 
elements of the blood in the living state, with their origin 
and the phases of their existence, in so far as they are con- 
stituent elements of the organism. Coagulation is a post- 
mortem phenomenon. 
I shall speak in the first person, giving credit where 
credit is due to others as well as to myself. 
It is not a little peculiar that the formed elements of the 
blood, which have been so long known, should be so little 
known. 
Even to-day we cannot say that we know with absolute 
certainty how they originate (at least in the adult), how long 
they live, and what may be their fate, for it is certain that 
their existence is relatively short. 
Every day one sees in the hospitals patients losing large 
quantities of blood, and it seems as though no one had asked, or 
at least had seriously considered and sought to discover, how 
it is that, at the end of a few weeks, the blood lost is entirely 
replaced. 
G. E. Rindfleisch, in calculating the replacement of blood 
in women during the intermenstrual period, estimated that 
half a centigramme must be produced in a minute, which 
means that about 175 millions of haematids are produced in 
the body every minute. 2 
How does this enormous proliferation come about? It is 
not a little hard to be obliged to confess that we are reduced 
* Translated from the ‘ llevue Scientifique.’ 
2 The term ‘ lioematid ’ is a rendering of the Frcncli term ‘ liematie,’ wliicli 
M. Pouchet uses to denote red corpuscle. 
