[9] Morton claimed the Bible supported polygenism, and working in a biblical framework, his theory stated that each race had been created separately and each was given specific, irrevocable characteristics.

"[12] Aside from this occasionally dark-skinned Caucasian ruling class, Morton's skull measurements led him to admit "Negroes were numerous in Egypt but their social position in ancient times was the same that it now is, that of servants and slaves.

[14] Morton's skull collection was held at the Academy of Natural Sciences of Philadelphia until 1966, when it was transferred to the Penn Museum, where it is presently curated.

[18] Morton believed that cranial capacity determined intellectual ability, and he used his craniometric evidence in conjunction with his analysis of anthropological literature then available to argue in favor of a racial hierarchy which put Caucasians on the top rung and Africans on the bottom.

[19] He described the Caucasian as "distinguished by the facility with which it attains the highest intellectual endowments"; Native Americans were described as "averse to cultivation, and slow in acquiring knowledge; restless, revengeful, and fond of war, and wholly destitute of maritime adventure" and the Africans he described as "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".

Gould's book became widely read and Morton came to be considered one of the most prominent cases of the effects of unconscious bias in data collection, and as one of the main figures in the early history of scientific racism.

[29] However, this study was reviewed in an editorial in Nature, which recommended a degree of caution, stating "the critique leaves the majority of Gould's work unscathed," and noted that "because they couldn't measure all the skulls, they do not know whether the average cranial capacities that Morton reported represent his sample accurately.

"[30] The journal stated that Gould's opposition to racism may have biased his interpretation of Morton's data, but also noted that "Lewis and his colleagues have their own motivations.

"[30] A 2014 review of the paper by University of Pennsylvania philosophy professor Michael Weisberg, tended to support Gould's original accusations, concluding that "there is prima facie evidence of a racial bias in Morton's measurements".

Weisberg concludes that although Gould did commit mistakes in his own treatment, Morton's work "remains a cautionary example of racial bias in the science of human differences".

Mitchell argues that Morton's interpretation of his data was arbitrary and tendentious; he investigated averages and ignored variations in skull size so large that there was significant overlap.

In another letter to Gliddon, December 14, 1849: "By the hands of the person to whom you confided them, I last night received Lepsius's "Chronologie," and the tin case of fac-simile drawings.

In another letter to Gliddon, January 30, 1850: "You allude to my altered views in Ethnology; but it all consists in regarding the Egyptian race as the indigenous people of the valley of the Nile.

"[36] In a letter to Mr. Bartlett on Dec. 1, 1846, he wrote: "My later investigations have confirmed me in the opinion, that the valley of the Nile was inhabited by an indigenous race, before the invasion of the Hamitic and other Asiatic nations; and that this primeval people, who occupied the whole of Northern Africa, bore much the same relation to the Berber or Berabra tribes of Nubia, that the Saracens of the middle ages bore to their wandering and untutored, yet cognate brethren, the Bedouins of the desert.