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.
Aunque se basaban en muy poca evidencia, muchos científicos pensaban que los cerebros de todos los mamíferos, incluyendo el cerebro humano, estaban formados de la misma manera, con un número de neuronas que era siempre proporcional al tamaño del cerebro.