Octopamine has been found in very high concentrations in cerebral and subpharyngeal ganglia of the earthworm
Lumbricus terrestris and may function as a neurotransmitter in the peripheral nervous system.
I thank Drs.A. Boulton, A. V. Juorio andP. H. Wu for helpful discussion and Dr.B. Davis for a sample of N, N-dimethyloctopamine. Support in the form of a M.R.C. of Canada fellowship is acknowledged.