—Of the lipid metabolic changes in Wallerian degeneration, the decomposition of phosphatides was studied in the early stages, 2–14 days after the nerve had been cut. It was found that the decomposition of phosphatides begins only 6 days after section. The amounts of lipid-P and fatty acid ester decrease in parallel. However, a greatcr decrease in the amount of fatty aldehyde was observed than of the lipid-P and fatty acid ester; this indicates that the vinyl ether bonds of glycerophosphatides are more sensitive to the degenerative process than the fatty acid ester or phosphorus.

The fatty acid ester: lipid-P ratio, calculated from the results, does not change; however, the fatty aldehyde: lipid-P ratio shows a marked decrease during this same period. The values of the ratios indicate that in the 2nd week following nerve section, decomposition of glycerophosphatides containing fatty aldehyde (i.e. plasmalogens), in contrast to glycerophosphatides of diacyl form, may be only partial. Thus, in the 2nd week of Wallerian degeneration the formation of lysophosphatides may be presumed to come from the plasmalogens.