The Fibonacci sequence of numbers, an infinite series, was defined mathematically, in Part One, to be

**Fn = Fn˗₁ + Fn˗₂**.

Their sequence begins, 0, 1, 1, 2, 3, 5, 8, 13….

The question arises, how do these numbers manifest themselves in nature, around us? What is their significance, their métier?

**Fibonacci on Land**

There are numerous manifestations of the Fibonacci sequence in nature. Quite a few are listed at the University of Surrey mathematics web-site. The site explains Fibonacci’s problem of the multiplying rabbits that lead, in the year 1202, to his namesake sequence.

Although the logic behind that problem contains a number of flaws, it did introduce Fibonacci and his sequence to us. A real occurrence of Fibonacci numbers in nature can be seen in the bottom of a pine cone.

**Fibonacci in the Sea**

Perhaps most inspiring is the occurrence of the Fibonacci numbers is seen in a sea-dwelling creature. The Fibonacci sequence, if visualized as a sequence of squares drawn in clockwise fashion (as in these images) can be seen to form a spiral. Compare that spiral with the cutaway shell of the nautilus.

The concluding, **Part Three**, of this series of articles will discuss *the significance* of these occurrences of Fibonacci’s numbers in nature.

**References:**

- University of Evansville, Indiana: Fibonacci