Regular and systematic pattern of growth such that the mass or size of any organ or part of a body can be expressed in relation to the total mass or size of the entire organism according to the allometric equation: \[Y = b{x^{\alpha}}\] where \(Y\) = mass of the organ, \(x\) = mass of the organism, \(\alpha\) = growth coefficient of the organ, and \(b\) is a constant.