Correspondence Charles Darwin v15

In 1867, Darwin focused on research that led to significant works, including Descent of Man and Selection in Relation to Sex. He distributed a questionnaire to explore human expression and sexual differences in the animal kingdom. Concurrently, he was engaged with proof-sheets for Variation of Animals and Plants under Domestication while regularly communicating with translators. This period marked a crucial phase in his scientific inquiries, reflecting his dedication to understanding evolution and human expression.