308 THE STRUCTUEE OF FLOWERS. 



anastomose with the dorsal cord ; these, together with the 

 greatly thickened cellular margins now constituting the 

 placentas which supply the conducting tissue for the pollen- 

 tubes, all show a form of hypertrophy in the edges of the 

 carpellary leaves, a condition of things widely different from 

 the usually thin and more or less impoverished margins of 

 true leaves. 



If we may recognize a fibre- vascular cord as the " funda- 

 mental unit," and as a basis for the construction of any 

 organ, and moreover as also containing within it poten- 

 tially the power of evolving any number of similar organs by 

 repeatedly branching ; then, when hypertrophy affects such a 

 " unit," it may branch once, twice, or any number of times, 

 when each branch passing off to the surface can lay the founda- 

 tion of a repetition of the organ from which it takes its rise.* 

 Attention has already been called to this origin of the 

 numerous stamens of the MaVoacece, and how certain forms 



of double flowers originate from the multi- 

 i Psl r~^ plication of the petaline cords, each branch 



of which issues in a distinct petal, as, in 



Snowdrops. 



Similarly for carpels and ovules, the 



process of multiplication can be witnessed 



both normally and .abnormally. On the 

 Fig. 88.— Multifold carpels one hand, that of carpels into five groups 



withovuliferousmargiDS , _^.,_, ., ^ 



from a malformed Prim- occurs in the Hollyhock through the 

 chorisis of the original carpellary cord ; on 

 the other. Fig. 88 represents a multifold carpel of a Prim- 

 rose, due, there is no doubt, to a like chorisis of the cords 

 belonging to one individual carpel. 



Similarly for ovules, while two only are normally charac- 



* I mnst again remind the reader tbat I am here Bpeaking meta- 

 phorically J as we do not know wherein this potentiality really lies, but 

 can only describe what is actually visible. 



