(273) 



SUMMARY. 



The volume is divided into three main sections : 

 Differentiation, Simplification, and Adventitious 

 Flowers. 



Under the heading of Differentiation are grouped 

 the following phenomena. 



Proliferation : this is of two kinds, viz. median and 

 axillary. The former concerns the main axis of the 

 inflorescence or flower, the latter the lateral out- 

 growths. Both kinds may be either reproductive or 

 vegetative. It is a reversionary phenomenon. 



Forking and Fasciation : these are essentially the 

 same phenomena as have been described for the Stem. 

 There is no real difference between normal and fas- 

 ciated inflorescences and flowers. As in the stem, 

 there are two types of fasciation, ordinary and ring- 

 fasciation. The latter is due, morphologically, to 

 lateral invagination of the external parts. Both kinds 

 represent stereotyped stages in the division of the 

 inflorescence or flower. 



Disruption : this consists in the splitting of the 

 maize-cob, or female inflorescence, into its primitive 

 constituents or branches which had become fused to- 

 gether to form the " cob." The result is a paniculate 

 inflorescence resembling the male one. 



Positive Dedoublement : this is " polyphylly," the 

 increase in number of the members of a whorl, or 

 " pleiotaxy," the increase in number of the whorls. 

 The tendency of an organ to divide overrides the 

 tendency towards unity. It is described with reference 

 to all the floral whorls and to the sporophylls of 

 Cryptogams. The phenomenon is generally a rever- 

 sionary one. 



Dialysis : the dissociation of members belonging 

 both to the same and to different whorls. A rever- 

 sionary phenomenon. 



VOL. II. 18 



