On Growth and Form

The problem of the growth of a natural form once the form is established is defined as: at the same angle a relative increase in length caused by a relative increase in number of cells. It's just like a problem in perspective or trying to increase a digital picture in size without losing sharpness. By length I mean extension at one point ( length, width, height)
Concentric circles as Escher shows solve the problem of length and angle. The logarithmic spiral as Darcy Thompson shows also solves the problem of increasing lengths at the same angle. The log spiral is the path between concentric circles.
Cells increase - but in what ratio? It could just as well be Fibonacci as geometric and Fibonacci would be better for keeping everything aligned on a spiral.
To unite everything in alignment, .618 could have been used in spiraling growth which solves all the problems because .618 is a number, a length, an angle and a ratio. But so far God only knows what really happened.