Scale and the gestation periods of animals
If the scale of an animal in creased will maintaining the same shape the mass of a fetus would be proportional to the cube of the scale. The nutrients to build the fetus must pass through the umbilical cord whose cross section has increased only with the square of the scale. Thus to the first approximation the gestation period should be proportional to the scale. The weight of the animal is proportional to the cube of the scale so the getstation period of animals of the same shape, say quadrupeds, should be proportiona to the cube root of the weight.
This conjecture is checked and confirmed empirically in the webpage.