Page:The Journal of geology (IA journalofgeology21894univers).pdf/397
petrographer, by the examination of a mere handful of specimens gathered hastily as a "last thought," is asking too much! There is a limit to what can legitimately be expected of paleobotany, just as there is a limit to all knowledge.
Again, it has frequently been a practice among geologists to submit a collection of fossil plants without indication of the specific information desired or even of the locality whence the specimens came. This is done presumably with the idea that the paleobotanist, being unembarrased with previous information, would be the better able to give an unbiased opinion. This again is wrong, and under such circumstances the paleobotanist would be amply justified in declining to express an opinion. Unless he can be placed in possession of all the information known to the geologist, or, what is better, have an opportunity of examining the relations of the horizons himself, he should hesitate before passing judgment. Of course, as pointed out under the discussion of principles, certain broad conclusions may be made instantly, such as the presence of dicotyledons proving an upper Mesozoic age, or Lepidodendra and Sigillaria arguing a Paleozoic age. These, however, are not usually the problems presented, but close questions of age, as, for example, the Miocene or Pliocene age of the auriferous gravels of California.
It has been argued by many, especially botanists and geologists, that it is undesirable to give names to fragmentary and seemingly indeterminable plant remains. When a definite name is given it implies, it is argued, a more exact knowledge than is often times possessed; a view that in many cases is undoubtedly correct. But the name is given, when the fossil cannot be made out satisfactorily, for purely practical reasons. It embodies, or should, the best possible judgment as to its nature and systematic position, and serves as a convenient basis of future mention of it without tedius circumlocution.
The foregoing examples have been given somewhat in detail, for the purpose of showing what has already been done with fossil plants, and to indicate the lines along which, it is hoped, increased assistance will be rendered geology in the future. These