440 BOTANICAL GAZETTE [NOVEMBER 
1. RELATION OF PINES TO CycADS.—‘‘Inverse wood,” such as 
occurs in the petioles of cycads, may be demonstrated on the 
ventral side of the protoxylem in juvenile leaves and needles of 
~ 
- 
=D 
_— 
rd 
DI)NN NDVI 
Fics. 1-3.—Transfusion sheath in needles of Pinus gana! (needle 2 years old, 
collected phe 5, 1918, section 5 mm. above base): fig. 1, part of wood in vascular 
undle; c, cambium, still dormant; x, wood of second year, vessels staining deep red 
with phloroglucin; v, wood of first year (protoxylem), spiral vessels, not staining with 
phloroglucin; 0, lacuna; s, inverse wood, staining light red with phloroglucin, bright 
green with meth Yemen, — with Sudan III; r*, resin canal; fig. 2, detail of inverse 
wood (shaded tissue s), showing relation to protoxylem (v) and to pitted cells of 
periderm; o, lacuna; fig. 3, longitudinal section of same, showing spiral vessels of Pr0- 
toxylem (v) and inverse wood (s); 0, lacuna; a, pitted vessels; i, oxalate of calcium. 
* All the figures are from Pinus maritima collected at Arcachon, 
