200 



PRINCIPLES 



OF PLANT-TERATOLOGY. 



eliminated, the result would be that the lower surface 

 of the lowermost lamina would be in contact with the 

 similar surface of the uppermost lamina. The apex 

 of the midrib of this last is prolonged into a short- 

 bare portion springing from the upper surface of the 

 lamina iiear its apex, this position being due to the 

 fact that its two apical lobes have fused behind the 

 midrib ; the bare piece of midrib thus springing 

 from the upper surface of the uppermost lamina 

 represents the nucellus of the leafy ovule. In this 

 foliage-leaf of Codixnm, therefore, the arrangement and 

 relationships of the three parts are exactly as they are 

 in the leafy ovule, consisting of outer and inner 

 integuments and nucellus. 



Again, in the pitcher-plant {Nepenthes) the basal, 

 fiat, assimilating portion of the leaf may be compared 

 with the outer integument in these ovules, and the 

 pitcher, whose stalk sometimes springs from its lower 

 surface, is comparable to the inner integument with 

 the upper surface inrolled. Eichler has described 

 almost equally instructive abnormal foliage-leaves in 

 Michelia. 



Indeed, it is quite frequent for the foliage-leaves 

 of many plants to exhibit the same structure that we 

 meet with in the leafy ovule, viz., a basal part bearing 

 a pitcher-shaped upper portion as an outgrowth from 

 its lower surface, or producing the stages which lead 

 up to this. Celakovsky observed such leaves in the 

 lilac (Syringa vulgaris) (PI. XLIX, fig. 6). They have 

 been seen in Loniceva conjugalis and Phlox paniculata 

 (see Vol. I, under " Enations ") ; in the latter the upper 

 division of the lamina is in the form of a long, tapering, 

 naked piece of midrib. Celakovsky even observed a 

 petaloid stamen of Camellia having precisely this 

 structure : the expanded filament bore on its dorsal 

 surface (directed inwards) a pitcher-shaped upper 

 portion representing the anther, whose outer surface 

 was morphologically the lower (PI. XLIX, fig. 7). 



Attention may further be drawn to the strong 



