It's all fascinating. I'm sure I will enjoy reading Darwin much more when I am older and have observed more of the world and evolved my own ideas relating to it.
"...indeed, we were capable of inducing a complete compound eye on an antenna, on a wing, or on a leg... We actually showed, later, that the fruit flies can see with these eyes."
Not any specific animal, but any animal (or person) that had gross deformities or severe birth defects might have been called a "monster" before about the middle of the twentieth century.
http://www.pbs.org/wgbh/evolution/library/04/4/text_pop/l_04...