THE LEAF. 



199 



lens is in which all the leaves on the tree without 

 exception have basal pockets, the inner surface of 

 which is morphologically the lower (PL XVII, fig. 4). 

 In a leaf of Glycosmis pentaphylla the same conforma- 

 tion has been seen. 



To all such cases as the above, C. de Candolle has 

 given the term " hypoascidia." To those about to be 

 described he gives the name " epiascidia." 



In these cases (the majority) the inner surface of 

 the pitcher is the upper, as in an ascidium of 

 Pelargonium zonale,*- which was fairly symmetrical in 

 shape ; in some such leaves a very small ascidium was 

 developed from one of the veins on the outer (lower) 

 surface ; in accordance with the law, the outer surface 



Fig. 54. — Brassica oleracea. Transverse section of " hypoascidium " 

 (diagrammatic), x, xylem ; ph, phloem. 



of this small pitcher Avas also morphologically the 

 lower (PI. XVII, fig. 5). A similar formation of a 

 basal pocket formed towards the upper side occurred 

 in a terminal foliage leaf of Buddleia Hemslnjana. 

 The same type of pitcher has been observed in Saxifraga 

 ligulata (PI. XVIII, figs. 1 and 4), Tilia, and Ulmus 

 glabra. 



c. Laminar " Enation*" — There is a quite different 

 type of " enation " from that of pitcher-formation. 

 The laminar outgrowths from the mid rib of the 

 cabbage-leaf have already been mentioned. Poh/gonum 

 cuspidatum has furnished excellent instances of this 

 phenomenon ; in some leaves there was an outgrowth 

 along either side of the midrib for the greater part of 

 its length on the lower surface of the leaf (fig. 55 a) ; 



f Vuillemin states that the rosette-leaves of Geranium macrorhizum are 

 normally pitcher-shaped. 



