176 Professor Dickson on tke 



belongs manifestly to the upper leaf-surface. In the perfect 

 pitcher the " lateral lines " are distinctly recognisable as 

 ridges, one on either side, running from the junction of the 

 corrugated rim with the base of the lid down towards the 

 extremity of the petiole, where they disappear. 



To convert, in idea, one of the funnel-like structures 

 above described into the normal CepAa/o^MS-pitcher, we 

 must imagine that side of the funnel nearest to the main 

 axis as remaining comparatively stationary, while the far 

 side of the funnel becomes calceolately pouched to an enor- 

 mous extent, forming, in fact, almost the entire pitcher. 

 The pitcher-leaf of Cephalotus, with its calceolate pouching, 

 whereby the apex of the lamina is curved round so as to 

 become approximated to its base, may not inaptly be com- 

 pared to the well-known " hammer-headed" upper petals of 

 Aconitum, where we have also petiolated leaf-organs with 

 similar pouching of the lamina and approximation of 

 apex to base. The interest of this comparison is further 

 heightened by the circumstance that in both cases the 

 internal surface is developed (although for very different 

 purposes) as a secreting apparatus. In illustration of the 

 parallel, I give an outline figure of the pitcher-leaf of 

 Cephalotiis (Plate V., fig. 6), placed in such a position — 

 with petiole nearly vertical — as will enable any one at a 

 glance to compare it with the nectariferous petal of Aconi- 

 tum (Plate V., fig. 7), a figure of which I have borrowed 

 from Prof. Asa Gray's " Text Book." 



The conclusions to which I have been led may thus 

 briefly be stated : — 



1st. That the pitcher results from a calceolate pouching 

 of the leaf-blade from the upper surface. 



2d. That the apex of the leaf is on the far side of the 

 pitcher-orifice from the main axis and from the lid, and is 

 probably represented by the tip of the middle dorsal wing. 



3d. That the pitcher-lid represents an outgrowth or 

 excrescence from the upper leaf-surface. 



In this place I must mention that Dr Masters, in his 

 " Teratology " (p. 314), says that "in Cephalotus follicular is 

 rudimentary or imperfect pitchers may be frequently met 

 with in which the stalk of the leaf is tubular, and bears at 

 its extremity a very small rudimentary leaf- blade." Unless 



