154 W. H. GILHURT ON THE 



fungous growtli is found to be extending into them from an ostiole 

 and distending them." 



The structures here described and the origin ascribed to them 

 were so at variance with anything of which I. had read or observed, 

 that, I confess, a doubt arose in mj mind as to their existence, and 

 yet they were described so circumstantially that I could not reject 

 them. I therefore aj^plied to Kew for specimens, and by the kind- 

 ness of the Curator obtained all I required, and was thus enabled to 

 satisfy myself as to their existence or not. 



It was not long before I arrived at the conclusion that Dr. Tait 

 was mistaken in his observations ; that his intercellular canals were 

 not present, and that the tubular trichomes described must have 

 originated as do all such organs ; but what it was which he had 

 interpreted as a canal I was at a loss to make out, till that portion 

 of his article treating of Nepenthes appeared, when I obtained a 

 clue which seemed to explain it all, save the statement that he had 

 seen '' fungous growth " in the canals. 



That he was mistaken will, I think, be made apparent as we 

 proceed in dealing with the several species. 



With regard to the general histology of all the genera, it will be 

 sufficient to say that in the main they agree with ordinary leaves, 

 the epidermis is continuous over both surfaces, and the arrangement 

 of the intervening tissues, the mesophyll, is very similar, those cells 

 next the outer surface of the pitchers being smaller and closer 

 fitting, thus corresponding with the pallisaded layer of the upper 

 surface of a typical leaf ; adjoining that and extending to the inner 

 surface cells is a very loose parenchyma, enclosing many and large 

 intercellular spaces, the vascular system ramifying amongst the cells 

 in all directions. The stomata are found in great abundance upon 

 the exterior of the pitchers and likewise on the upper zone of their 

 interior surface. 



The Pitcher plants belong to four different genera, viz., Sarra- 

 cenia, Darlingtonia, Cephalotus, and Nepenthes ; and, together, con- 

 stitute a group as interesting as they are unique. 



The species of Sarracenia of which Dr. Tait gives the fullest 

 description, is S. pvrpnrca. The interior surface of this pitcher is, 

 as lie points out, divided into four zones. On the first one, or that 

 nearest the mouth of the pitcher, are numerous stomata, and also a 

 large number of strongly developed rigid hairs, which point down- 



