Text Book of Biology, Part 1: Vertebrata · H. G. Wells — chapter 59 of 285 · ~21 words · public domain
are usually cubical or polygonal (8, g.ep.), and they display in the most characteristic form what is called metabolism. Anaboly (see
Text Book of Biology, Part 1: Vertebrata · The Wunder Library — complete classics, free to read, with narration.