1232 A TEXTBOOK OF THEORETICAL BOTANY 



type of carpel which produces it. It is probable, nevertheless, that the 

 ventral condition is the primitive one in Angiosperms, as it is shown by 

 most of the " primitive families " in the group, such as Ranunculaceae, 

 Butomaceae, Alismaceae and especially by the Winteraceae and some of the 

 Magnoliaceae, as we shall see below. Rare exceptions to these general 

 conditions do occur, in the case of fully peltate pouch-carpels, such as those 



Fig. 1 1 90. — Carpels of Driniys. A, Sub-gen. Tasmannia, carpel opened showing pal- 

 mate three-veined vasculation and margins entirely stigmatiferous. B, Sub-gen. 

 Wintera. Side view showing restricted stigma. Dotted line shows comparative 

 length of stigma in Tasmannia. {After Bailey and Nast.) 



of Chloranthus and other Piperaceae, where there are neither ventral nor 

 dorsal sides, nor indeed any suture, but there is only a sessile stigmatic 

 area at the apex. Peltate stigmas, on the other hand, where they are formed 

 at the end of a true style {e.g., Rheum), are not necessarily an indication of 

 peltate carpel structure, but do not differ fundamentally from the globose 

 or knob-like terminal stigmas, which are quite common. 



The two modes of formation of the dorsal stigma and its supporting 

 style, which we have detailed above, correspond in fact, and perhaps in 

 origin, to the two types distinguished by Hunt on the basis of the theory, 

 put forward by Eames, of the origin of the carpel from a palmately three- 

 lobed structure, originally a dichotomous syntelome. Hunt distinguishes 

 first, stigmas w^hich are formed from the middle (dorsal) lobe only, our 

 first dorsal type, which contain only one vascular bundle, and secondly 

 those which are formed by the approximation of all three lobes and contain 



