Lastly, the instance cited by Dr. Allman[462] in Saxifraga Geum may be alluded to. Here there was a row of adventitious carpels between the stamens and pistils, the backs of the carpels being turned towards the axis of the flowers. Dr. Allman explains the presence of the supernumerary parts by the supposed production of a whorl of secondary axes between the stamens and the centre of the flower. These axes are further supposed to bear imperfect flowers, of which the additional carpels are the only traces, but this explanation seems forced.
In addition to the references already cited the following may be given:
Duchartre, 'Ann. Sc. Nat.,' 4 ser., vii, p. 23 (Tulip).
Ferrari, 'Hesperides,' pp. 271, 395, 405. Duchartre, 'Ann. Sc. Nat.,' 4 ser., 1844, vol. i, p. 294. Maout, 'Leçons Elément.,' vol. ii, pp. 488–9. Clos, 'Ann. Sc. Nat.,' 1865, p. 317 (Citrus Aurantium).
Clos, 'Bull. Soc. Bot. Fr.,' vol. xiii; 'Rev. Bibl.,' p. 75. Pasquale, 'Reddicont Accad. Sc. Fis. e Math. Napoli.' Octr. 1866 (Solanum Lycopersicum).
On the general subject of multiplication, in addition to previous citations, the reader may be referred to A. P. de Candolle, 'Théorie Elément. Bot.,' ed. 3, p. 89.
Increased number of flowers in an inflorescence.—This happens generally as a result of over luxuriant growth, and scarcely demands notice here, being rather referable to variation than to malformation. The increased number of florets in the spikelets of some grasses has already been alluded to (p. 351). Thus spikelets of wheat occasionally produce more than the three florets which are proper to them.[463] It will be remembered that in this as in many other grasses there are rudimentary florets, and it is no matter for surprise that these florets should occasionally be fully developed.
FOOTNOTES:
[392] 'Bull. Soc. Bot. Fr.,' vol. vii, 1860, p. 587.
[393] 'Fragment. Phyt. Austral.,' part xx, p. 270.