"No practical biologist interested in sexual reproduction would be led to work out the detailed consequences experienc…"

"No efforts of mine could avail to make the book easy reading."

"We may consequently state the fundamental theorem of Natural Selection in the form : The rate of increase in fitness …"

"Professor Eddington has recently remarked that 'The law that entropy always increases -- the second law of thermodyna…"

"[We are now] in a position to judge of the validity of the objection which has been made, that the principle of Natur…"

"In organisms of all kinds the young are launched upon their careers endowed with a certain amount of biological capit…"

"An important question raised by both the Batesian and the Mullerian theories of mimicry concerns the process by which…"

"The gregarious habit of certain larvae supplies a possible solution of the problem, if we are willing to accept the v…"

"A book that I rate only second in importance in evolution theory to Darwin's Origin (this as joined with its suppleme…"

"This is perhaps the most important book on evolutionary genetics ever written."