196 THE REV. G. HENSLOW ON THE ORIGIN OF FLORAL ASTIVATIONS. 
of the bundle continues its way to the notch at the summit of the lobe, and branches 
within the lobe. Now this is identically the same as in the calyx of Prunus, in which, 
as in the corolla of Primula, there are five median bundles, which do not bifurcate 
until they arrive at the lobes. Тһе five bundles alternating with the petal-lobes of 
Primula or calycine lobes of Prunus bifurcate also on arriving at the notch between 
the lobes. Тһеу then send off dichotomously branching members up the adjacent edges 
of two lobes—that is, of two different members of the whorl. 
The conclusion I would draw is this—that the calyx-tube of Prunus is homologous 
with the petioles, the lobes with the blades, and that the same holds good for the 
corolla of Primula; and I think we are justified in concluding that the corolla of the 
latter is а veritable foliaceous whorl. 
Moreover the sestivation of the corolla of Primrose is strictly the same as in many 
other plants, and, if analogy is to be trusted, confirms this belief. Lastly, what is of 
chief importance is, that the theory being based, as no doubt is the only sound method, 
on development, is, however, as I interpret the facts, based on а misunderstanding of 
them—namely, that because the stamens appear first, and the lobes of the corolla suó- 
sequently (but they arise as soon as the anther is developed, and are all connected бу а 
horizontal band), therefore the latter is an outgrowth of the androecium. But, as has 
been already observed, invariably acropetal or centripetal development of the whorls of 
flowers does not occur. That the corolla-lobes should develop after the stamens is by 
no means without parallel; for it occurs in many plants, as in the few following ex- 
amples, in which the whorls are written in order of development :— 
Ranunculus acris: Cal., St., Pi., Cor. 
Stellaria holostea: Cal., St. opp. pet., St. opp. sep., Pi., Cor. 
Lychnis dioica: same order, but without Pi. 
Veronica chamedrys: Cal., St., Pi., Cor. 
Cerastium glomeratum (self-fertilizing): Cal., Pi., St. opp. sep., St. opp. pet., Cor. 
Arenaria trinervis (do.) : same order. 
