LECT. X.] ANATOMY OF LEAVES. 597 



miles; and a. that the lateral partitions between 

 the cavities, apparently consist of square cells, 

 when transversely divided, as in the figure before 

 us, although they are hexagonal, when viewed 

 laterally, as in the diaphragm. Each cavity is 

 lined on every side with a thin pellucid pellicle, 

 closely resembling the external cuticle ; and 

 frequently hairs, knobs, and similar cuticular 

 productions are found projecting into these cavi- 

 ties. Kieser, who is the only author who has no- 

 ticed these bodies, remarks that he had sometimes 

 observed, in the cavities of Calla -^Ethiopica, small 

 globular, pedunculated bodies ; which, springing 

 from the sides, project towards the centre of the 

 cavities ; but, according to my observations, they 

 are more common in those of Typha, Equisetum, 

 and Nymphcea, in the latter of which they closely 

 resemble the branched hairs (see Plate 9, fig. 14.), 

 which form the tufted pubescence on the under 

 disks of some leaves. 



In closing this view of the anatomy of the 

 cellular system of leaves, I have to remark, that 

 although it embraces the more common varieties 

 that are met with, yet it is probable that, in the 

 vast range of the vegetable kingdom, many other 

 diversities of structure of the cellular matter exist. 



From these inquiries into the structure of the 

 vascular and cellular systems of leaves, the affinity 

 which exists between the stem and the leaf is very 



