found a strong and general tendency on the parts of both the floral envelopes and sexes to change

In the

to leaves, like the leaves of the stem. white clover (Trifolium repens, fig. 9.), all the parts often become leaves; in the Fraxinella (fig. 10.) this has also been remarked; so has it in the Nasturtium, in Sieversia montana, and many other instances. A partial alteration into leaves is of very frequent occurrence in the parts of a flower. In the

Rose, the sepals and pistil are frequently changed into leaves; in the Double Cherry, the pistil is almost always to be found in the form of a leaf;

Proceedings of the Horticultural Society, vol. i. p. 37.

and books on structural botany abound in the records of similar cases. It sometimes happens that buds are not only formed,

but developed, at the axils of the parts of a flower, as in a Celastrus scandens observed by Kunth. (fig. 11.) In the Pear, it is not uncommon to

find two or three small pears growing out of an older one (fig. 12.), each of which pears may be traced to the axil of some one of the parts of the flower; and rose-buds are frequently seen growing out of Roses. A very striking and uncommon case of this sort was observed

by the late Mr. Knight in the Potato (fig. 13.), whose flowers produced young potatoes in the axils of the sepals and petals.* Occasionally, the centre of a flower lengthens and bears its parts upon its sides, as in the Pear and Apple, whose fruit is often found in the state of a short branch. Still more rarely a flower lengthens, and

*

fig. 2.

Proceedings of the Horticultural Society, vol. i. p. 39.

produces from the axils of its parts other flowers arranged over its sides, as in the Double Pine-apple of the Indian Archipelago. The following very striking illustrations of these facts have, among many others, occurred in the present season (1839). Fig. 14. represents a branch of a Pear in which one flower (a) is in a deformed state, but still sufficiently recognisable, and another completely changed into a branch; the calyx assuming the appearance of leaves or leafy scales (ss), the petals also partially transformed into leaves (pp), while the whole apparatus of stamens and pistils is converted into an ordinary branch. Fig. 15. shows the state of plants of Potentilla nepalensis with their flowers changing to branches: a is a flower in the ordinary condition; at b it is partly changed in a slight degree; at c all the sepals, petals, and stamens are converted into leaves, but the pistils are little changed; at d the sepals, petals, and stamens are but little altered,

but the receptacle of the fruit is lengthening into a branch, and is covered by the carpels partly

converted into leaves, and some of them near the apex producing flowers from their axils; finally, at e, the whole of the floral apparatus is changed into a rosette of leaves. It therefore appears, that although the parts of a flower are