Page:Carroll Lane Fenton - A History of Evolution (1922).djvu/67

 64 before. Paleontologists are studying their fossil shells and corals and bones in order to find out what has taken place during the millions upon millions of years during which living things have inhabited our planet. Anatomists are studying the bodies of modern animals, from the simplest to the highest, to determine their relationships one to the other; embryologists are tracing out the evolution of the individual in his life before birth. The geneticists are breeding plants, rabbits, mice, fishes, flies, potato bugs so that they may discover what evolution is doing today. Everywhere men are studying, comparing, experimenting. Their purpose is not to discover whether or not evolution is a fact; on that point they have long ago been satisfied. They are trying to find out how it operates and what forms it has produced; how differences arise among organisms, and what are their effects, and by what means they are passed from one generation to another until they become part and parcel of the inheritance, thereby establishing a new species.