DESCRIPTIVE CATALOGUE 



to fit. They average about 10-20 /n in diameter. Their walls 

 are thick, but not excessively so, apparently about the dia- 

 meter of the whole wall. Their pits are round and bordered, 

 as can clearly be seen in PI. XXVII, fig. 2, p. Wood-paren- 

 chyma appears to be present in rather small quantities, and in 

 the transverse section shows thinner walls than the fibres and 

 has dark contents. Medullary rays are so numerous in the 



Text-fig. 78. Cnntia arborcscens, sp. nov. Tangential view of part of two 

 rays, a vessel and fibres: m., ordinary cells of medullary ray; ., end- 

 cells of ray ; v., wood-vessel, across the lumen of which can be seen the 

 end- walls of tyloses, t. X nearly 400. Iso. V. 13231 /. 



longitudinal sections that I have not been able to determine the 

 nature of the cross-walls of the parenchyma. Medullary rat/- 

 cells are all alike, save for minor differences in shape (text- 

 figs. 77, 78, and PI. XX VI J I, fig. 2). Their walls are all con- 



