THE PALEONTOLOGIC RECORD 333 
THE PALEONTOLOGIC RECORD 
THE RELATION OF PALEOBOTANY TO PHYLOGENY 
By Prornssor D. P. PENHALLOW 
McGILL UNIVERSITY 
| eas history of plant life has been the central idea in all botanical 
studies from the very earliest times, whether expressed in the 
imperfect methods of the early German and Dutch botanists who de- 
sired simply to establish natural affinities on the basis of external re- 
semblances, or in the ambitions of Cesalpino to arrive at a classifica- 
tion of plants which should satisfy the conditions of relationship 
through the structure of all parts, and especially of the reproductive 
organs. For nearly four hundred years the external organs have been 
employed as the chief basis of those numerous systems of classification 
which have appeared from time to time. The idea that the reproduc- 
tive organs and the minute interior structure of plants were of primary 
importance as first advocated by Cesalpino, was for a long time lost to 
view, although it reappeared now and then in the works of later writers. 
Eventually it gained recognition and became a factor of increasing im- 
portance, until the most advanced systems are now employed involve an 
acceptance of both the external parts and the internal anatomy as es- 
sential factors. 
From the time of Malpighi and Grew, to Goeppert and Corda, our 
knowledge of the interior structure of plants made great and rapid 
progress, and was later applied successfully by various investigators im 
the direction of establishing relationships. To no one are we more 
fully indebted for an elaboration of this idea than Williamson, whose: 
researches into the structure of fossil plants from the Coal Measures 
of Great Britain, during the latter part of the last century, laid the 
real foundation of modern paleobotany. 
In so brief a treatment as that which is now employed, it is impos- 
sible to more than touch upon some of the salient features in the rela- 
tions of paleobotany to the course of phylogeny, but it is, nevertheless, 
worth while to give special emphasis to the now well-recognized fact 
that a thorough knowledge of the interior structure of the plant, and 
especially of the stem, leads to a more comprehensive and exact ac- 
quaintance with relationships than that of any other part. This arises 
from the fact that the minute anatomical details have a greater degree 
of stability than any other portion of the body, doubtless due to the fact 
that in its adjustment to the land habit, the environmental influences 
