How to Interpret Figure 1

We are counting the number of pairs of rabbits, not individual rabbits. Therefore, each square represents one pair of rabbits. If that square lacks an interior color (i.e. the square is white inside), then it is a newborn rabbit and is not yet sexually mature. If the square's interior is blue or orange, then it is mature and mating. The blue and orange are only meant to show generations. (Blue gives birth to orange, and orange gives birth to blue.) If the square's interior is green, then it is no longer living and should not be counted. This green square is only there to illustrate that the rabbits die after giving birth one last time.

Take for example, month six.


There are five squares one blue, one green, one orange, and two white.
Because we can't count the green square, in month six we only have four pairs of rabbits.