246 SECTIONAL ADDRESSES, 
of descent, and to a large extent independently of particular life 
conditions. 
It seems to me that no structure which has been assumed to be 
homologous throughout a large series showing many gaps is really safe 
from the suspicion of having been developed independently on different 
lines of descent. In a recent paper Dr. Scott writes ° of the inference 
‘that the Seed Plants, of which the Pteridosperms are among the earlier 
representatives, constitute an independent phylum, of equal antiquity 
with any of the recognised lines of Vascular Cryptogams.’ But is it 
at all certain that the Seed Plants really constitute a single phylum ? 
Is it not perfectly possible that the seed with its attendant mechanisms 
has been independently evolved in some or all of the six classes of 
Seed Plants which, apart from the Angiosperms, ave now recognised ? 
It is clear that the more such suspicions effect permanent lodgment in 
our minds the more uncertain all wide positive phylogenetic conclusions 
must become. 
Meanwhile the whole of this branch of botany seems to leave the 
great majority of the younger botanists cold. No longen under the 
lunmediate influence of the revolution in biological ways of thinking 
brought about by Darwin, they are not greatly interested in comparative 
morphology, nor in the attempts to disentangle the past history of the 
plant kingdom, sustained and even magnificent as these attempts have 
been, and greatly as they have enriched our knowledge of the past life 
of our world. There is, to many of them, an effect of hopelessness and 
even of futility in the effort to trace out the course of the threads in an 
intricately woven carpet, with no attainable certainty that we have got 
them right, however long and patiently the task is pursued, partly 
because so many of the threads, such large portions of the carpet, have 
been destroyed for ever, partly because, as Professor Seward suggests, 
we may, in effect, be dealing not with one carpet, but with many. 
While we may urge that far too much time has been, and in many 
places still is, devoted to the study of comparative morphology in 
elementary teaching, it is impossible to deny the great interest and 
importance of conclusions like those quoted from Dr. Scott and Professor 
Seward. From the point of view of the ideal of the ‘ genealogical 
tree ’ these conclusions are negative, but they are none the less interest- 
ing and valuable, for they are giving us a truer view of the past history 
of plants. 
There has certainly been no less of interest in the process of develop- 
ment, whether phylogenetic or ontogenetic. The unfolding of life upon 
the earth, the marvellous story of development and change, of increasing 
complication and endless variation on the one hand, and on the other 
the great problem of how the complex organism comes to develop from 
the minute zygote, can never lose their fascination for the human 
mind. It is the formal comparison of the end results of this process, 
with a view to the determination of phylogenetic relationships, the treat- 
ment of the problem as’‘ a purely historical one,’ which seems to so 
many of the keenest younger biologists a hopeless and not a very 
® I'he Origin of the Seed Plants, p. 227. 
