GENEEAL MORPHOLOGY OP THE PLANT 93 



faces are directed laterally like those of phyllodes. Its con- 

 struction can be determined by an inspection of its base, 

 where it is seen to be split partly up one edge, the split embracing 

 the next leaf. The blade is, in fact, folded along its centre, and 

 the upper surfaces of the folds are united together along nearly 

 the whole of the lamina. One edge of the blade so corresponds 

 to the conjoined margins of the leaf, the other to its central line, 

 and the two sides to the whole dorsal surface. The upper surface 

 is only exposed at the sheathing base. 



Scaly 0)- Cataphyllary Leaves. — These are of very simple 

 structure, and may generally be regarded as leaves that have 

 remained rudimentary. They occur as coverings to buds and 



Fig. 188. 



Fig. 189. 



Fig. 190. 



Fiif. 188. Pitcher of a species of Pitcher-plant {^^epe7>t/^f•s distillatot-ia). 



p. Pitcher coverecl by the lid, 1. /"iV/.'lSg, Pitcher of the Side-sadrlle-plant 



(Sarraceniu purpurea). Fuj. 19U. Pitchers of Heliamplwra. 



thin membranous coatings to tunicated bulbs and corms. The 

 i3eshy leaves which form the bulk of tunicated or scaly bulbs 

 may be included here. They do not contain chlorophyll, and are 

 consequently never green in colour. In some parasitic and 

 saprophytic plants, such as the Broom-rapes, and certain orchids, 

 fleshy scales replace the ordinary foliage leaves. 



Floral Leaves. — These include the various forms which occur 

 in connection with the mechauisrhs of spore production. They 

 will be discussed later in more detail. They show much 

 peculiarity of form, colour, and arrangement. 



