Icones cerebri simiarum et quorundam mammalium rariorum.

"Although a few more reports were published furing the next hundred years [after Tyson] it was Tiedemann alone who gave a more detailed account, on monkeys, in his... Icones Simiarum.... In monkeys he found the brain shorter, the sulci shallower, and both sulci and gyri far fewer than in the human brain....in monkeys, as also in the ape, he observed greater symmetry and regularity of the convolutional pattern than is generally seen in man (Meyer, Historical aspects of cerebral anatomy, 142). Digital facsimile of the 1821 edition from Google Books at this link.