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SCIENCE 



[N. S. Vol. XXXII. No. 820 



a classic, but like some other classics it has 

 little except a historic interest at the present 

 time and is not comparable to the contem- 

 poraneous work of Brongniart or Sternberg. 



It is reassuring to see that British paleo- 

 botanists have readmitted ferns to the Paleo- 

 zoic flora after having banished them almost 

 completely a few years ago, and another 

 praiseworthy feature of Miss Stopes's book is 

 her recognition of the grave objections to the 

 derivation of the angiosperms from the Meso- 

 zoic cycadophytes. To mention certain points 

 which strike the reviewer as misleading, it is 

 very doubtful if the older Paleozoic was of 

 longer duration than the balance of time since 

 its close. Again, Newer Mesozoic, Upper 

 Mesozoic and Upper Cretaceous are used as 

 synonyms, and if we are to understand that 

 Lower Mesozoic includes Lower Cretaceous 

 then monocotyledons and dicotyledons are well 

 represented in the Lower Mesozoic of both 

 Europe and America, despite the author's 

 statement to the contrary. 



The wide differences between floras of pre- 

 Tertiary epochs are entirely fictitious, and it 

 may be questioned if some of the Triassic 

 " Equisetites " are not nearer the Paleozoic 

 Calamites than they are to modern equisetums. 

 It is true that Neocalamites and Pseudannu- 

 laria are not petrified, but they are almost 

 wholly unlike Equisetum. The differences 

 between the Permian and Triassic floras has 

 the sanction of long-continued reiteration, but 

 that the statement is venerable does not make 

 it true, and the more we know of the some- 

 what scant floras of the earlier Triassic the 

 more Paleozoic their affinities appear. 



If in an elementary work it is permissible 

 to speak of Lepidodendron and its allies as if 

 they were club-mosses it seems like straining 

 at a gnat to insist that the Mesozoic Bennet- 

 titales, so-called, were not cycads. The dif- 

 ferences between Cycadeoidea, to use the cor- 

 rect term, and modern cycads is scarcely 

 greater than between Lepidocarpon and Lyco- 

 podium. Incidentally the author seems to 

 have forgotten the rather numerous impres- 

 sions of Paleozoic cycadophytes. 



Miss Stopes's statement that fructifications 



are always the most important part of the 

 plant will depend entirely upon the plant con- 

 sidered and the point of view. The estab- 

 lished fact of the plasticity of the reproductive 

 parts in most of the great Paleozoic plant 

 phylae is clear evidence that they furnish less 

 reliable data for the determination of their 

 points of contact with later plants than is fur- 

 nished by stem anatomy or even foliar char- 

 acters. A striking instance of a similar sort 

 is furnished by the analogy between the so- 

 called flowers of the Mesozoic cycadophytes 

 and those of angiosperms. 



Chapters VIII. to XVIL, dealing with the 

 past histories of plant families, are in the 

 main well written, although that devoted to 

 the angiosperms is relatively poor, as is usually 

 the case in all discussions of this class of 

 plants. The author's caution regarding the 

 value of negative evidence in dealing with 

 the Cretaceous flora seems to have been for- 

 gotten in her consideration of the very spe- 

 cial kind of a flora which the Carboniferous 

 rocks have almost universally yielded, and it 

 may also be worth mentioning that other fac- 

 tors besides a cold season will account for 

 leaf fall, and annual rings, so-called. 



For those who have read thus far and have 

 wondered what excuse the book has for its 

 existence it may be pointed out that it is the 

 only modern attempt at a summary of our 

 present knowledge in the field of paleobotany. 

 The author is quite at home in the realm of 

 anatomy and morphology and gives a very 

 readable summary of the present state of 

 knowledge in this field which has been so 

 admirably tilled of late years, particularly by 

 the botanists of Great Britain. The chief 

 defect of the book is the attempt to spread 

 the morphology and anatomy of the Carbonif- 

 erous swamp-flora, or the concepts derived 

 from its study, over all geological time the 

 world round. 



It is perhaps unfair to expect an avowed 

 primer to be a manual, nevertheless it remains 

 true that a satisfactory paleobotanical text, 

 either elementary or exhaustive, which will 

 maintain a proper balance between fossils 

 showing the external form of plants and those 



