FORMATION OF SUGAR IN THE LIVER. 577 
the vital influence, it consists in the transformation of the 
glucogenic matter into sugar with the aid of a ferment. 
The reunion of these tw ? o orders of conditions is necessary 
for the appearance of sugar in the liver. The glucogenic 
matter must be created by the vital activity of the organ ; it 
is then necessary that this matter should be brought in con- 
tact with the ferment which is to convert it into sugar. 
The glucogenic matter is formed like all the products of 
organic creation, by means of the phenomena of slow circu- 
lation which accompany the acts of nutrition. As for deciding 
if, amid the numerous blood-vessels with which the liver is 
provided, there be any which are peculiarly charged with this 
nutritive circulation and others peculiarly connected wdth the 
phenomena of the chemical transformation of the glucogenic 
matter, that is a physiological question upon which it is at 
this moment unnecessary to enter. It will suffice for us to 
indicate in a general manner how the contact between the 
glucogenic matter and its ferment may take place in the 
living animal. 
I at first thought that the ferment w ? as peculiar to the 
liver, like the glucogenic matter itself ; I had even succeeded 
in obtaining it in an isolated state. But, seeing afterwards 
that the sanguineous fluid possesses the property of trans- 
forming this glucogenic matter into sugar w’ith the greatest 
readiness, it became impossible to think of a localization of 
the ferment ; that extracted from the liver coming, very pro- 
bably, from the blood itself. So that if out of the organism 
we have several ferments which operate the transformation 
of the glucogenic matter into sugar, in the living animal it is 
only necessary to admit one represented by the blood, which 
moreover possesses the property of rapidly changing hydrated 
vegetable starch into dextrine and sugar. Without entering 
into the intimate mechanism of this contact, and into the 
explanation of the physiological causes which vary its 
intensity, w hich w T ould lead us into descriptions of microscopic 
anatomy and phenomena of capillary circulation which will 
be developed elsewffiere ; we shall confine ourselves to saying 
that the observation of physiological phenomena teach us 
that in the liver, parallel with this slow and nutritive circu- 
lation, there must be considered another, intermittent, 
variable, and whose superactivity coincides with the ap- 
pearance of a larger quantity of sugar in the tissue of the 
organ. 
In digesting animals the circulation in the vena porta is 
super-excited, and then the transformation of the glucogenic 
substance is much more active, although the formation of 
