The Need for an Internal Skeleton

The need for an internal skeleton stems largely from the nature of muscle tissue, which can exert force only by contracting and is therefore much more effective with a good lever system to work with. I belittle neither the intelligence nor the strength of the octopus; but in spite of Victor Hugo and most other writers of undersea adventure, the creature's boneless tentacles are not all that effective as handling organs. I don't mean that the octopus and his kin are helpless hunks of meat; but...

 The Beauty of Comparative Anatomy

It is one of the most beautiful interests of that beautiful science, comparative anatomy, to trace the complex and wonderful adaptations of living things to the necessities of existence in air. All living things, plants and animals alike, are primarily water things. For example all the higher vertebrated animals above the fishes, up to and including man, pass through a stage in their development in the egg or before birth in which they have gill slits which are obliterated before the young em...

 Mark Twain's Description of Evolution

Adam is fading out. It is on account of Darwin and that crowd. I can see that he is not going to last much longer. There's a plenty of signs. He is getting belittled to a germ—a little bit of a speck that you can't see without a microscope powerful enough to raise a gnat to the size of a church. They take that speck and breed from it: first a flea; then a fly, then a bug, then cross these and get a fish, then a raft of fishes, all kinds, then cross the whole lot and get a reptile, then work...

 Pride in Evolutionary Ancestry

How I hate the man who talks about the 'brute creation', with an ugly emphasis on Brute. Only Christians are capable of it. As for me, I am proud of my close kinship with other animals. I take a jealous pride in my Simian ancestry. I like to think that I was once a magnificent hairy fellow living in the trees and that my frame has come down through geological time via sea jelly and worms and Amphioxus, Fish, Dinosaurs, and Apes. Who would exchange these for the pallid couple in the Garden of ...