Abstract

As a rough measure of intelligence, brain weight: cord weight ratios in small delphinids compared favorably with, but were slightly less than , this ratio in man. Not all delphinids studied were found to achieve the minimum 1000 gm brain weight correlate of language development in the human child. The average adult brain size in some small pelagic cetaceans was found to be about 800 gm, while the average for Tursiops truncatus, an estuarine species, was found to be about 1450 gm.