CRETACEOUS CONIFERALES 21 
adopted, it follows that only the actual occurrence of the substance in 
organic connection with coniferous remains can constitute good evi- 
dence as to the origin of such amber. A great deal of this material 
from Kreischerville is in all probability bark amber, and constitutes 
the indurated remains of the resin, which once flowed in the cortical 
tissues of extinct conifers; but it is not generally possible to definitely 
connect such amber with its coniferous source. Fortunately, how- 
ever, in some of the Kreischerville material amber was actually found 
in situ in fragments of lignites, and, in all such cases which we have 
had the opportunity to examine, the correlated wood was found to 
belong to Pityoxylon statenense. It 15 not improbable, however, as 
has been suggested by Conwentz in the case of the Baltic amber, that 
the same type of Pityoxylon may have represented the wood of sev- 
eral different species of pines. 
In fig. 1, Pl. 23, is shown a succiniferous fragment in transverse 
section, X 10, from the Drummond pit. The amber cavity appears 
along the upper margin of the figure and is clothed with the same 
abnormal lining of parenchyma as has been described by various 
authors who have written on the Tertiary amber of the Baltic region. 
The numerous light spots over the surface of the figure indicate the 
presence of more or less normal resin canals, similar to those found 
in the wood of living species of pines. In fig. 2, Pl.-23, is shown 
another view of the same type of succiniferous Pityoxylon, likewise 
in transverse section, X 10. Theamber cavity appears in this instance 
in the upper left-hand region of the figure. Figure 3, Pl. 23, repre- 
sents the lining of a part of the amber cavity, X 20. It may be 
noted that there is present a thick Jacket of traumatic parenchyma, 
quite similar to that described by Goeppert, Conwentz and others in 
the case of the succiniferous woods of the Baltic deposits. Similar 
cavities, as is well known, occur as a pathological feature of the wood . 
of living pines. Figure 4, Pl. 23, shows another transverse section, 
X 40, of the structure of a well preserved fragment of apparently 
the same species of Pityoxylon. Normal resin canals of the vertical 
type are present in numbers, while a single horizontal canal may be 
distinguished. 
As has been pointed out in the paper on Cretaceous Pityoxyla 
above cited, the fossil pine woods of the Kreischerville deposits differ 
from living pines in the absence of the marginal tracheids from the 
medullary rays. Since this marked feature occurs also in the cones 
