FcDis of Europe and the Atlantic Islands. 258 



tory, but, when following out the idea, he puts Pteris, Allosorus, 

 Cheilanthes, and Adiantum, with Gymnogramme and Polypodium, 

 into one tribe, makes a second of Blechnum, Woodwardia, Athy- 

 rium, Asplenium, Scolopendrium, Camptosorus, and Ceterach 

 (defining this last as destitute of involucre) ; a third of Phegopteris, 

 Aspidium, Cystopteris, Onoclea, and Woodsia ; and in a fourth 

 puts together Davallia and Nephrolepis. he gets groups which, in 

 our view, are neither natural nor capable of being characterized 

 clearly. 



Following principally the lead of Dr Mettenius, whose recent 

 death in the prime of life is a loss to fern-literature which can 

 scarcely be estimated too highly, the later German writers on ferns 

 have adopted a much more technical and systematized terminology 

 than has ever been used in this country. This has the disadvan- 

 tage of making their books so much more difficult for the non- 

 initiated to understand, and in some cases we certainly think they 

 have gone further in this direction than is compensated by any 

 advantage Avhich they obtain in precision in defining species or the 

 groups of various values. For instance, they recognize eight dis- 

 tinct types of free venation, which Dr Milde defines in his preface 

 and refers to sometimes, but not invariably, in his descriptions, 

 called the veining of Cjenopteris, Ctenopteris, Pecopteris, Tteniop- 

 teris, Sphenopteris, Eupteris, Neuropteris, and Cyclopteris. We 

 submit that this is overdoing the thing, and that it would be better 

 to reduce the types to four, as follows : — 



1. A distinct unb ranched vein carried into each ultimate divi- 

 sion, as in Hymenophyllum Tunbridgense. 



2. Ultimate divisions with a distinct midrib and simple or forked 

 veins branching from it, as in Scolopendrium, Lomaria spicant, 

 Pteris aquilina. 



3. Ultimate divisions with a distinct midrib and pinnated 

 veinlets branching from it, as in Aspidium aculeatum, Nephrodium 

 filix-mas, &c. 



4. No distinct midrib but the veining flabellato-dichotomous, 

 as in Adiantum capillus-veneris, and Botrychium lunaria. 



Will not this, expressing the cutting of the frond in the ordi- 

 nary way, simple, pinnate, bipinnate, tripinnate, pinnatifid, bipin- 

 natifid, tripinnatifid, answer every practical purpose ? 



It may be useful also to some of our readers if we explain 

 their terminology of what may be called the architecture of the 

 frond. For the general outline of the frond, Dr Milde has three 

 terms, which certainly is not systematising too much, " pyrami- 



