Or LOWER GREENSAND PLANTS. 



scales leave the axis at an acute angle, and appear to measure 

 about 4 cm. from tip to attachment. In transverse section 

 (PL X, fig. 4; text-fig. 30) they have an approximately 

 triangular outline. As there are no longitudinal sections, it 

 is impossible to determine whether the bract-scale persists 

 separately from the large ovuliferous scale. 



Lying against the upper surface of the scales, towards the 

 inside of the cone, two symmetrically placed, narrow, scale-like 

 structures can be seen (PI. X, fig.4, w.\ text-fig. 30, /.), evidently 

 the massive wings of the seeds, which must have been already 

 ripe and almost ready for dispersal at the time of petrifaction. 

 The tissues of the scales are perfectly petrified in some cases, 

 and consist of large roundish cells, the majority of which have 

 much thickened and sclerised walls (PI. XI, fig. 3, scl.} ; towards 

 the edge of the scales they are much smaller and form a some- 

 what irregular limiting layer, the original epidermis being 

 apparently disintegrated. JJetween the limiting layer of the 

 inner surface of the scale and the two wings, which are generally 

 free from it, two rows of smaller softer cells can be seen in a 

 few places, showing that they originally formed part of the same 

 tissue. 



Itesin-canals of some si/e are irregularly scattered throughout 

 the tissues of the scales (PI. XI, fig. 3, r.c. ; text fig. 30). The 

 vascular bundles of the free outer part of the scales are 

 numerous, bi-lateral, with some tendency to be curved, and, in 

 a few cases, almost circular. Their arrangement can be seen 

 in PI. XI, fig. 3, v.6., and in the text-fig. 30, where it will be 

 noted that toward the middle of the scale the bundles are in an 

 irregularly double series, oriented at a variety of angles toward 

 c;ich other. The main bundles, however, are so oriented that 

 iheir xylem is directed away from the inner face of the scale, 

 which is thus its morphologically lower surface. The significance 

 of the anatomy of the cone-scales of Pinus has been discussed 

 by van Tieghem (1869), Eichler (1881), Worsdell (1900), and 

 others ; and it will bo of interest to compare the theoretical 

 consideration of living species in these papers with the details 

 of this, the oldest, Pinus-like fossil in which the vascular 

 anatomy of the scale is known. 



At the base of the scale, near the attachment of the ovules, 

 the bundles are united to form two flat bands, oriented so that 



