Let us remember that topology and the theory of numbers sprang up in part from that which used to be called “mathematical entertainments,” “recreactional mathematics.” I salute in passing the memory of Bachet de Meziriac, author of Problèms plaisants et delectable qui se font par les nobres (1612—not, as Larousse says, 1613), and one of the first members of the French Academy. Let us also remember that the calculation of probabilities was at first nothing other than an anthology of “diversions,” as Bourbaki states in the “Notice Historique” of the twenty-first fascicle on Integration. And likewise game theory until von Neumann.
- The arrangement of leaves or other lateral members (e.g. the scales of a pine cone, the florets of a flower of the family Asteraceae ( Compositae), etc.) on an axis or stem; the geometrical principles of such arrangement.
Below are mathematical functions for variant phyllotaxis shapes found in organic structures, and, even more fantastically, their nomenclature.