On the structure and function of a neurohemal organ in the eye cavity of Eledone cirrosa (Cephalopoda).

The subpeduncualte lobe of the octopod brain produces a hormone that is released into the orbit. The hormone was extracted from Eledone cirrosa and assayed on the isolated perfused heart of the same species. It has a remarkable effect on amplitude, beat frequency and blood pressure; compared to equivalent extracts of posterior salivary gland it is about 70 times more effective. The substance is not a biogenic amine.