Cunning Jiamia sinensis. 597 
in the Infracretaceous, this being the oldest well authenticated record of 
the occurrence of any of the four genera, Cedrus , Tsuga , Abies, and Pseudo - 
larix (Fliche, P., Etudes sur la Flore fossile de l’Argonne, Bull. Soc. Sci. 
Nancy, 1896). Fliche’s observations are all the more significant, because it 
is precisely the genus Cedrus which on anatomical and experimental grounds 
we should regard as the most ancient of its series, for by its wound reactions 
it shows a closer relationship to Pinus than any of the three allied genera, 
in that the traumatic resin-canals occur in both the horizontal and vertical 
planes, instead of in the vertical plane only, as in the remaining three 
(Jeffrey, E. C., Comparative Anatomy and Phylogeny of the Coniferales, 
II, Abietineae, Boston Society of Nat. Hist. Memoirs, 1905). It follows 
both because there are strong reasons for regarding Pinus as a very 
old representative of the Coniferous stock, and because Cedrus , Tsuga , 
Abies , and Pseudolarix show clear indications of descent from ancestors 
possessing at least the ligneous characteristics of Pinus , that there are good 
reasons for regarding the Abietineae as an ascending series, beginning with 
more complicatedly organized forms like Piims , and terminating with 
simplified genera like Abies and Pseudolarix. The views stated here are in 
strong opposition to those expressed by Penhallow in his recent works. 
They seem, however, to rest on sound anatomical and palaeobotanical 
evidence. Professor Penhallow has not brought forward any good evidence 
for his view that the ligneous resin-canals of Pinus and its allies are derived 
from aggregations of the resin-parenchyma, which is found in the 
Taxodineae and Cupressineae. His view is that the resin-canals appear 
first as imperfect cysts in the wood and afterwards become organized into 
a perfect system of resin-canals, such as is characteristic of Pinus. Professor 
Penhallow has failed to recognize that his resin-cysts are always of trau- 
matic origin, and are not a normal feature of wood structure as he assumes. 
Further, if we for the sake of argument were to admit Professor Penhallow’s 
hypothesis, we should encounter the difficulty that the resin-canals not only 
have to develop from the imperfect cysts, but that these have in the course 
of evolution to become connected with each other and with the perfect 
cortical system of resin-canals, since in Pinus not only the ligneous canals 
form a complete system, but these are also in continuity with those found 
in the inner bark. There is every reason to believe that, in the forms with 
resin-canals less perfectly developed among the Coniferales, we have rather 
to do with the isolation of parts of a once complete system as the result of 
degeneration than the opposite process, as is indicated by Professor 
Penhallow’s hypothesis. Further, not only in the matter of the degeneracy 
of the ligneous resin-canals are Pseudolarix and Abies the uppermost terms 
of the Abietineous series, but also in the loss of the other characteristic 
feature of the living Abietineae, viz. the marginal tracheids of the medullary 
rays. In Pseudolarix marginal tracheids have quite disappeared, while in 
