Vy iia 
M. Coste on the Formation of Cells. 97 
had assumed regular forms, and in each vitelline sphere had ac- 
quired a generating activity which becomes a powerful cause of 
multiplication. 
There is then a distinct organic form, which may be considered 
as a primary act of individualization, or a primary manifestation 
of life, between the amorphous state of this matter and its actual 
application to the formation of the cellular walls. This primary 
act or this primary manifestation has for its object the forma- 
tion of granular spheres, which, without being bounded by an 
enveloping membrane, have already a true existence, are true 
livmg individuals, inasmuch as they enjoy the faculty of repro- 
duction, and in multiplying they become the active elements of 
the organism, and contribute to the formation of the tissues of 
which the organism is composed. 
For my own part, I am unacquainted with anything which is 
more curious to observe than this progressive duplication of living 
spheres reproducing in each secondary segment the reduced but 
invariable image of the primary vitelline sphere. And in pro- 
portion as we witness the realization of this remarkable pheeno- 
menon, we are as it were involuntarily led to seek, in the interior 
of the substance which is doubled, some material arrangement 
which may explain a metamorphosis, the cause of which cannot 
be clearly found elsewhere. 
In fact, a more attentive examination soon shows that in the 
centre of each vitelline sphere there exists a diaphanous homo- 
geneous globule having a fatty aspect, and which cannot be com- 
pared to anything better than a drop of oil. Seeing that this 
globe appears in so constant a manner, we inquire if the division 
of the vitel/us cannot be attributed to its influence. But in order 
to solve this problem, what passes in this same vitellus prior to 
its division, and when it consequently appears as a simple sphere, 
should be examined. 
We then see that the fatty or oleaginous globe, hidden in the 
midst of the granulations of the primitive sphere, there undergoes 
a contraction which divides it into two segments or distinct glo- 
bules, and each of these segments seems to become a centre, which 
tends to envelope itself in a portion of the surrounding granula- 
tions, separating them from cells which are entangled by its fellow. 
We should say, in short, that the vitelline sphere, excited simulta- 
neously by two centres of action, yields to each of these centres 
half the substance of which it is composed, and thus divides into 
two segments which are immediately rendered spherical; each 
segment of the vitelline sphere, being furnished with the oleagi- 
nous globule which has excited the separation, then becomes in 
its turn the seat of a similar process, and the division of its cen- 
tral globule induces that of the secondary sphere which contains 
