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 1 1 |    man and bird bipeds, but fish footless; and why do man
 2 9 |   we have said before. Flat fish use two fins, and the flat
 3 9 |    pair of fins. Quite flat fish, like the Ray, produce their
 4 10|  the fins, for instance, in fish. In others, for example
 5 15|     in the yielding medium, fish in the water, birds in the
 6 18|  creatures having feet, but fish none. The former have their
 7 18|   must therefore have feet. Fish on the contrary live in
 8 18|    superior part, similarly fish have two pectoral fins;
 9 18|  the wings; similarly, most fish have two fins on the under
10 18| Birds, too, have a tail and fish a tail-fin.~