In Darwin’s time no serious attempt had been made to examine the manifestations of variability. A vast assemblage of miscellaneous facts could formerly be adduced as seemingly comparable illustrations of the phenomenon “Variation.” Time has...

It was in the attempt to ascertain the interrelationships between species that experiments n genetics were first made. The words “evolution” and “origin of species” are now so intimately associated with the name of Darwin...

Of the contributions made during the essayist period three call for notice: Weismann deserves mention for his useful work in asking for the proof that “acquired characters” or, to speak more precisely, parental experience can...