1914] CURRENT LITERATURE 75 
acid includes also an explanation of the primary origin of characteristic building 
stones of lecithins, since the acids of the proteins and the alcohols of the lecithins 
arise through one and the same reaction. This would explain SToKLAsa’s 
finding that protein and lecithin-formation always run parallel. The formal- 
dehyde, formed by the reduction of CO, in green plants, is condensed to gly- 
colaldehyde. By the Cannizzaro reaction, one molecule of glycol and one 
molecule of glycollic acid arise from two molecules of glycolaldehyde. These 
products furnish aminoethylalcohol and glycocoll by aminization. 
CH,—OH 
| c +H,0= 
H 
os 
CH.—OH COOH 
glycolaldehyde glycol glycollic acid 
CH, oat OH 
+NH;= CH.—NH, 
Cc H, Sia OH “f H, O 
ae OH 
glycol aminoethylalcohol 
CH,—OH CH,—NH.+H,0 
COOH +NH.z= COOH 
glycollic acid aminoacetic acid (glycocoll) 
This reaction furnishes, therefore, the simplest amino acid, the mother sub- 
stance of the simplest betain and aminoethylalcohol which may give rise to 
cholin by methylation as noted above. Analogous with the above reaction a 
furthur condensation of formaldehyde is postulated for the formation of 
glycerinaldehyde, and from this may arise glycerin and serin by the reaction of 
Cannizzaro and by aminization. We now have the glycerin for the formation 
of fats, lecithin, and other phosphatids. The higher amino acids may be con- 
sidered derivatives of serin, and alanin a reduction product of the same. The 
author denies the probability of HCN being an intermediate substance in the 
Primary formation of proteins. 
The author extends his hypothesis to the mechanism of methylation. By 
the reaction of Cannizzaro, formaldehyde can furnish methyl alcohol and formic 
acid. The methyl alcohol can in turn furnish the alkyl groups for the methyla- 
tion of metabolic products. Since this scheme is based upon the work of the 
chlorophyll apparatus, it will not explain the mechanism of the methylations, 
which frequently occur in animals. 
The Cannizzaro reaction is accelerated by the enzyme aldehydase, which 
has been definitely proven in this case to be a hydrolytic enzyme. In addition 
to this, if oxygen is present, the alcohols formed at the same time can be 
oxidized. We have here a case of an enzyme accelerating both hydrolysis and 
oxidation. ae 
