459 



D e s c r i p t i ( » n o i" t li e c 1 e m u n t s. 



I. Vessels. R. and T. 28 to 40 /<, about 88 /« bciiig thc 

 commonest size. Roughly circular cylinders. Transverse 

 îvaUs X)laced very ohliquely; with scalariform perforations 

 and horizontal nmgs, see flg. 1'). Walls 

 thickened, but not remarkably so and 

 the lignified wall much thinner than that 

 of the adjacent cells (fibre-tracheids); — 

 with irregularly placed simple round or 

 slightly oval pits (p. 86). 



II. Fibre-tracheids R. and T. 15 to 

 50 (?) /«, the radial dimension often 

 somewhat smaller than the tangential ; 

 4- to 6-, generally 6-angular. Walls in 

 most cases thickened, the lumen of the 

 cells ,'■; or less that of its whole dia- 

 meter (see PL 8 Photo 10 and text- 

 fig. 1); — with bordered pits, on the 

 tangential walls at least as numerous as 

 on the radial (p. 86, PL 8 Photo 10, and 

 text-fig. 1); arranged in 1 and in a fcw 

 cases in 2 slightly irregular rows, not 

 very closely arranged in vertical position, 

 each being spaced at a distance from 

 its neighbour roughly equal to its own 

 diameter; borders of pit-chambers circular (p. 86). 



III. Wood parenchyma. Cells on a traverse section some- 

 what elongated in the direction of the circiimfcrence of the 



Vig. 1. 



A}iliana ric^Uata 

 Stopes. Transverse 

 wallof vessel, sliow- 

 ing scalariform per- 

 l'o ration. Reproduc- 

 tion of text-fig. 2 of 

 Mrs. Stopes' papcr. 



1) On p. 80 Mrs. Stopes says: „In longitudinal section not 

 many of the vcssels show the charactcr of tlicir walls, but tliose 

 that do, havc broad, simple scalariform pitticg (sec tcxt-lig. 2)"'. If 

 a regular Linnean description had been madc, tliis raistakc wonld 

 no dcubt havc been avoided. 



