1223. But an originally septenary corolla is conceivable, if forsooth the energy of light is still in a condition to separate two bundles of fibres. How rarely this occurs is well known, and thus it still continues doubtful whether this form is not to be explained by an arrest of development.
1224. Nature can produce no originally octo-, deka-, or dodeka-petalous, &c. corolla.
1225. Corollæ with originally nine, eleven, and more numbers are not impossible. The last seem only to exist.
1226. All corollas having even numbered petals, originate through arrest of the odd leaflet.
1227. The number two originates most usually and in the simplest manner from the arrest of the number three. If it originates from the quinary quantity, two pinnate leaflets are then coarrested.
1228. The aberration is recognized either from the position of the lobes or petals that have been left remaining, or from comparison of the number in other parts, in the calyx and capsule.
1229. The quaternary corolla is a quinary without the uneven leaflet.
1230. The hexapetalous is a doubling of the tripetalous, corolla. There are two whorls of petals, provided the calyx has not become corolla-like in character. Both cases are demonstrable through the alternating arrangement of the parts.
1231. The number eight is a doubled four.
1232. Nine is indeed in most instances a product of three multiplied by three.