Within the last half century, the labours of such men as Von Baer, Rathke, Reichert, Bischof, and Remak, have almost completely unravelled... the successive stages of development which... are now as well known to the embryologist as are the steps of the metamorphosis of the silk-worm moth to the school boy.

Ch.2, p. 75. - Evidence as to Man's Place in Nature (1863)