274 NATURAL SCIENCE [October 
subject of fossil plants. Laymen might find in such a list of blunders. 
a mere comedy of errors, but the palaeobotanist must see in them 
serious warnings against dogmatic conclusions or expressions of 
opinion on imperfect data and insufficient evidence”; and it is in 
this spirit, not one of severe criticism, that we must study many of 
the earlier writers. 
Nomenclature is dealt with in chapter vi, and though a text- 
book is not the place to treat fully this “difficult and thorny ques- 
tion,” the general principles are laid down for the protection of the: 
name of the original describer as the author of the species, even 
though circumstances demand its removal to another genus than that 
in which it was originally placed. 
Part IL., beginning at chapter vii., deals with the systematic portion 
of the subject. The divisions of the plant kingdom are taken in 
their natural sequence, beginning with the lowest and passing 
gradually to the highest group. The Thallophyta are therefore 
first considered, the various groups or genera being preceded by 
a short account of their recent representatives. Here are included 
the Girvanella of Nicholson and Etheridge. The supposed fossil 
bacilli are described in some detail, and though some minute 
bodies are possibly correctly included here, a great deal of un- 
certainty hangs over many of these so-called Bacteria. 
The Algae form a difficult class. Undoubtedly most of the fossils. 
originally described as Algae are inorganic markings and animal 
tracks, though a few true Aleae have been found in the fossil state— 
even in palaeozoic rocks. Examples of tracks simulating Algoidal 
structures are given which will illustrate the difficulties in dis- 
tinguishing between true fossils and inorganic markings. We believe’ 
Mr Seward is correct in the doubts he holds as to the vegetable: 
nature of Chondrites verisimilis, Salter. 
It is impossible to refer in detail to the many interesting points. 
touched on by the author in his admirable treatment of this very 
difficult class of fossils, but Mematophycus — the Prototaxites of 
Dawson—deserves a passing notice. This plant is very fully gone 
into by Mr Seward, who arrives at the conclusion that “on the 
whole it is probably the better course to speak of Nematophycus as a 
possible ally of the brown Algae rather than as an extinct type of, 
the Siphoneae,” and this is going quite as far as our knowledge of the 
fossils warrants. 
In chapter viii. the Bryophyta are considered. We are here 
treading on very difficult ground, and especially in regard to those 
species discovered in the older rocks, none of which seem to be alto- 
gether free from doubt. 
When we reach the Pteridophyta, chapter ix., one possesses more 
certain data from which to form an opinion of the affinities of the 
various fossils described, though even here there is room for much 
difference of opinion. ; 
The Equisetaceae are first described,—a sketch of Hquisetwrm 
prefacing the study of its fossil allies, and here are met with some of 
the most interesting fossils one requires to consider. 
The genus Hguisetum has been recorded by several writers from. 
Palaeozoic rocks, but Mr Seward places all these in Hqutsetites, and as. 
