654 TRANSACTIONS OF SECTION K. 
logical workshops only ; with these and their uses the descriptive worker must 
be familiar, for the need to employ them may arise at any moment. If he 
does not always abandon old friends for new, this is not because the syste- 
matist is unaware of their existence, or unprepared to apply new methods. 
The descriptive worker employs his tools as a craftsman ; like other craftsmen, 
he finds that tools do not always fulfil the hopes of their designers. In 
descriptive work, too, as elsewhere, a steam hammer is not required to break 
every nut; the staff and sling may be arms as effective as those of the hoplite. 
There are occasions when the descriptive writer does appear to hold aloof by 
declining to accept proffered evidence. But his motive is not arrogant; it is 
only altruistic. If he is to avoid the risk of causing those who depend on his 
results to reason in a cirgle, the descriptive writer must obtain these results, 
if not without extraneous aid, at least without help from those for whose 
immediate use they are provided. 
Taxonomic study is pursued in an environment which differs from that 
surrounding descriptive work. 'The descriptive student can hardly see the 
wood for its trees. The taxonomic student works in more open country, and 
can look on the wood as a whole. He has, too, the benefit of companionship. 
The paleobotanist meets him, with all the lore of mine and quarry, as one 
ready to exchange counsel ; other workers attend to give or gather information. 
The community of interest which unites the systematic worker, chiefly con- 
cerned with existing plant-types, and the paleobotanist, primarily interested 
in types now extinct, is strengthened by the bond which identity of purpose 
supplies. But the two are differently cireumstanced ; the systematic worker is 
ordinarily better acquainted with the characters than with the relationships 
of his types ; the paleeobotanist usually knows more of the relationships of his 
types than he does, or ever may do, of their characters, The material of the 
paleobotanist rarely lets him rely on ordinary descriptive methods in defining 
his plants; he has to deptnd largely on anatomical evidence, which supple- 
ments and confirms, but hardly replaces, the data of organography. On the 
taxonomic side the paleobotanist is restricted to phylogenetic methods; here 
again he is handicapped, though less than on the descriptive side, by the frag- 
mentary character of his specimens. The palsobotanist hardly does more 
than the phylogenist, hardly as much as the anatomist, towards advancing the 
object all have in common. 
The same community of interest unites in their labours the organographic 
systematist and the morphologist whose interests are phylogenetic. Here, 
however, though the task of the two be complementary, the mode of attack is 
so different as almost to mask their identity of purpose. The comparative 
morphologist studies the planes of cleavage indicated by salient differences in 
structure and development. Thesystem he evolves is composed of the entities, 
sometimes more or less subjective, that combinations of characters suggest. 
The method in intention, and largely in effect, passes from the general to the 
more particular, though the process is tempered by the fact that the characters 
used are derived from such types as exhibit them. The organographic syste- 
matist, after summing up the characters which mark individual types, aggre- 
gates these according to their kinds. Having estimated the features that 
characterise individual kinds, he aggregates these according to their families. 
Families are thereafter aggregated in higher groups, and these groups are 
subjected to further aggregation. The system thus evolved is composed of 
those entities, always in theory objective, that successive aggregations indi- 
cate, and the process is one of constantly widening generalisation. 
The comparative morphologist, though glad when his results can be prac- 
tically applied, follows truth for its own sake. His work is thus on a higher 
plane than that of the organographic systematist, whose aggregations dre 
primarily utilitarian. But the work of the latter is not less valuable because 
its scientific character is incidental. Were our knowledge of plant-types 
exhaustive, a generally accepted artificial arrangement of these would be as 
