280 Reviews—The Life and Works of Prof. Oswald Heer. 
Aceriphyllum inequale. Then we should know at once that the 
former species had been proved to belong to the genus Acer, whilst 
the generic position of the latter was still uncertain. In this way 
the palzeobotanist would be able to express the precise aces ee of our 
knowledge of a fossil plant. 
Dr. Schréter is not an uncritical admirer of everything alain Heer 
has done, but whilst expressing the opinion that Heer had gone too 
far in determining genera from dicotyledonous leaves, he gently 
remarks that it has nevertheless been fortunate for science that he 
had the courage to proceed as far as he did, for otherwise a great 
number of fossil leaves, which have been rightly determined, and 
which have proved of the greatest value in furthering our knowledge 
of the geographical distribution of plants, and of the climates ‘of 
former epochs, would have been either overlooked or not described. 
And even supposing that in some cases Heer’s determinations of 
fossil leaves have been insufficiently based, these are more than 
counterbalanced by the importance of those correctly worked out. 
According to Dr. Schréter, the total number of new species described 
by Heer amounts to 1947, and, in addition to these, he has described 
numerous forms to which names had been already applied by others. 
These descriptions of fossil plants were accompanied by as many as 
704 plates. Heer had indeed the satisfaction to find that the merits 
of his works were acknowledged by most competent judges, amongst 
others by Sir Joseph Hooker, who pronounced, as his ‘candid 
opinion,” that at least two-thirds of Heer’s determinations of fossil 
genera and families were quite correct, and that those correctly 
determined included nearly everything of importance. Even Lyell 
was fully convinced of the correctness of Heer’s determinations of 
Tertiary plants. 
Under these circumstances it is probable that the attacks made, 
from time to time, on Heer’s methods and results, owe their origin 
either to imperfect knowledge, or to a misunderstanding of what he 
has done. Of course, since the time when Heer wrote there have 
been great advances made in paleeobotany, as in every other science, 
and it is not surprising, therefore, that the methods he followed 
should now be partly supplanted by better ones. But if we are to 
condemn every honest worker of a previous age simply because his 
methods do not agree with our own, who would then escape con- 
demnation? There is no doubt that Heer, in common with every 
other scientific writer, has made mistakes; but these are so much 
more than counterbalanced by the excellent work he has done, that 
it would be decidedly unfair to dwell only on the former, without 
taking the latter into account. 
Much has been written lately on the question whether certain 
deposits, pronounced by Heer to be of Miocene age, might not, in 
reality, belong to the Eocene. The question is still undecided; but 
even if some of these deposits should ultimately prove to be of 
Eocene age, it must not be forgotten that but little was known of 
1 For further details compare the paper by the reviewer in the “ Botanisches 
Centralblatt,’’ 1886, vol. 25, Ueber die Benennung fossiler Dikotylenblatter. 
