Though it was based on very little evidence, many scientists thought that all mammalian brains, including the human brain, were made in the same way, with a number of neurons that was always proportional to the size of the brain.
Iako je postojalo vrlo malo dokaza, mnogi znanstvenici su mislili da je mozak sisavaca, uključujući i ljudski mozak, sačinjen na isti način, s brojem neurona koji su uvijek proporcionalni veličini mozga.