F
Feeble-mindedness, [264].
Feet of mammals, [122].
First living things, [165].
Fish eggs, [145].
Fish may freeze, [104].
Fitz-Roy, Capt., and Beagle, [25].
Freedom of teaching, [291].
Fright paralysis, [108].
Frog's long tadpole stage, [112].
Frost and bluebirds, [61].
Fur of seal, [100].
Future evolution of man, [249].