PROLIFICATION OF THE FLOWER. 121 



phyllacecef Bosacece i while it is commonly met with in 

 Scrophulariacece, P^'iiaulacece, smdUmbelliferce. Of genera 

 which seem peculiarly liable to it may be mentioned 

 the following : Anemone^ Ranunculus^ CheiranthuSy 

 DianthuSy Dlctamnus, Daucus, Bosa, Geum, Pyrus, 

 Trifoliumy Antirrhinum ^ Digitalis , Primula. 



A reference to the subjoined list of genera affected by 

 this malformation, and the knowledge of its comparatively 

 greater frequency in some than in others of them, will 

 show that it is more often met with in plants having an 

 indefinite form of inflorescence than in those having a 

 definite one. The change may affect some only, or 

 the whole of the flowers constituting an inflorescence ; 

 and though it is by no means a constant occurrence, it 

 very frequently happens that the central or terminal 

 flower in a definite inflorescence is alone affected, the 

 others remaining in their ordinary condition, as in 

 pinks {Diantlms) ; and in the indefinite forms of inflo- 

 rescence, it is equally common that the uppermost flower 

 or flowers are the most liable to be thus affected. 



In those plants which present this deviation from 

 the ordinary condition with the greatest frequency, it 

 often happens that the axis is normally more or less 

 prolonged, either between the various whorls of the 

 flower, as in the case of the gynophore, &c., or into 

 the cavity of the carpels, as in the instances of free 

 central placentation. To bear out this -assertion, the 

 following instances taken from those genera having 

 definite inflorescence, and which are very commonly 

 affected with prolification, may be cited; thus, in 

 Anemone and Ranunculus the thalamus is prolonged to 

 bear the numerous carpels ; in Dianthus there is a 

 marked internode separating the carpels from the other 

 parts of the flower ; in Primulacece central prolification 

 is very common, and this is one of the orders where 

 the placenta seems, from the researches of Duchartre 

 and others, to be truly a production of the axis within 

 the carpels ;^ in Thesium also, another genus with 



' iDuchartre, ' Ann. des sc. nat..' 3me eerie, vol. ii, 1844, p. 293. 



