J 56 
ANNALES DE L’INSTITUT PASTEUR 
lhe exercise of sufficient care leucocytes can be obtained prac- 
tically free from bacterial contamination. Further the expe- 
riments with leucocytes can be carried out in usual Chemical 
flasks and test tubes, and therefore they permit of a quantative 
study of the products of the reaction. Hence one was encou- 
raged to see in lhe leucocyte the most satisfactory agent for 
the study of the process of glycolysis. The expectation was 
realised in a considérable degree. The work in tliis direction 
was begun by the présent writers in 1911, and is not yet com- 
pleted. Previous to the présent writers Lépine was inclined to 
ascribe to leucocytes the principal part in animal sugar 
combustion. Simultaneously with us Salte lias proved lhat 
through the action of leucocytes glucose is transformed into 
lactic acide The study of the action of leucocytes on hexoses 
has led lhe présent writers to the following conclusions. 
1) The hexoses are converted by leucocytes into lactic acid 
according to lhe following reaction : C 6 H 12 0 6 = 2C 8 H 6 0 3 . 
2) Lactic acid is apparently the final product of the reaction. 
When lactic acid is acted upon by leucocytes it remains 
unchanged. The quantity of lactic acid produced from hexoses 
by leucocytes is équivalent to the quantity of disappeared sugar. 
Ilowever the mechanism of this transformation is very 
complex. By the aid of leucocytes it was possible to elucidate 
some of its phases. 
A priori lactic acid may be produced from hexoses through 
the intermediate forma lion of glyceric aldéhyde. This in its 
turn may be transformed into lactic acid directly or through 
the intermediate formation of methylglyoxal. The process 
is made obvious by lhe following structural expressions : 
o 
I! 
C — H 
I 
H — G — OH 
I 
HO — G — H 
I 
H - G - OH 
! 
H — C - OH 
H — 
O 
il 
C — H 
I 
C — OH 
I 
ch 2 oh 
+ 
O 
II 
C — H 
ch 2 oii 
II — G — OH 
I 
CH s OH 
