Reproduction, [309]; amœba, [32], [35]; hydra, [38]; magosphæra, [40]; volvox, [41]; turbellaria, [50]; annelids, [62]; insects, [66]; vertebrates, [73]. See also [Size] and [Surface and Mass]
Respiration, amœba, [35]; worms, [48], [63]; insects, [66]; vertebrates, [77], [84]
Sequence of functions, [80], [109], [174], [309]; condensed history of, [100], [152], [221]; reversal of, [154], [205]
Sexual reproduction, [33], [37], [41]
Sin, [245]
Size, [35], [51], [72], [76], [89], [214]
Skeleton, [58], [74]; mollusks, [59]; insects, [65], [67], [71]; vertebrates, [74], [82]