In disposition the Negro is joyous, flexible, and indolent; while the many nations which compose this race present a singular diversity of intellectual character, of which the far extreme is the lowest grade of humanity.

He wrote Geological Observations in 1828 and both Synopsis of the Organic Remains of the Cretaceous Group of the United States and Illustrations of Pulmonary Consumption in 1834. Samuel George Morton (1799–1851) was an American physician and natural scientist. His bibliography includes Hybridity in Animals and Plants (1847) Additional Observation on Hybridity (1851) and An Illustrated System of Human Anatomy (1849).