STRUCTURE.] 



PHYTOCRENE NEPENTHES. 



while the pith itself is filled with bundles of fibre-vascular 

 tissue. This structure is represented by Adolphe Brongniart, 

 in the 1 6th volume of the Annales des Sciences. 



Mr. Griffith has beautifully illustrated the structure of 

 a plant called Phytocrene (fig. 36.), in Wallich's Plants 



fig. 36. 



Asiatics, vol. iii. t. 216. In this curious production the 

 wood consists of plates containing vessels and woody tissue, 

 having no connection with each other, and separated at very 

 considerable intervals by a large mass of prosenchymatous 

 cellular tissue filled with vasiform tissue, and representing 

 medullary rays. When the stem is dry, the woody plates 

 separate from the other tissue, in which they finally lie 

 loose. 



In Nepenthes distillatoria the pith contains a great quantity 

 of spiral vessels ; the place of the medullary sheath is occu- 

 pied by a deep and dense layer of woody tissue, in which no 

 vessels, or scarcely any, are discoverable ; there are no me- 

 dullary rays; the wood has no concentric zones; between the 

 bark and the wood is interposed a thick layer of cellular tissue, 

 in which an immense quantity of very large spiral vessels is 

 formed ; on the outside of this layer, is a thinner coating of 

 woody tissue, containing some very minute spiral vessels ; and, 

 finally, the whole is enclosed in a cellular integument, also 

 containing spiral vessels of small size. In this singular plant 



p 2 



