ON GENERA AND SPECIES. - 49 
$ 3. Pilularieæ (Gen. 1, Pilulariee, Lin.) 
§ 4. Marsiles (Gen. 1, Marsilea, Lin.) 
The above classification shows that Mr. Moore has be- 
stowed great ingenuity upon its formation, but I cannot 
view it otherwise than as an artificial arrangement founded 
upon certain technical data that normally characterise all 
true Ferns, whatever size, habit, or mode of growth they 
assume. "We need not therefore be surprised at finding, 
associated under the same sections, genera of extreme un- 
natural habit and mode of growth as also differing essen- 
tially in their vascular structure, such as Jenkinsia and 
Platycerium ; Monogramma, Hymenolepis, and Gymnopteris ; 
Lomogramma, Drymoglossum, and Tteniopsis; Brainea, Mi- 
miscium, and Dryomenes; Didymochlena and Mesochlena ; 
Calymmodon, Stegnogramma, Gymnogramma, Struthiopteris, 
Jamesonia, and Drymaria ; Onoclea, Polystichum, and Ne- 
| phrolepis ; Cystopteris and Humata; and Woodsia and Hy- 
_ poderris: the placing of these in their respective sections | 
being entirely guided by the character of the fructification, 
without regard to natural habit. Any system of classifi- 
_ cation of Ferns based upon these principles may be 
viewed as analogous to the Linnean classification of pheno- 
gamous plants. I 
I have now to notice the next part of this work, 
which consists of an alphabetical arrangement of the 
whole nomenclature of Ferns, collated from the publica- - 
tions accessible to the author, “and blended with such 
personal information as the author has been able to bring to 
bear upon the subject." In order to appreciate the extent - 
of this work, it is only necessary to state that up to Sep- 
ember, 1962,* 396 pages were published, and which ` ` 
> Up to the present time, 1874, no addition to the above has been ae Ge 
Mo. Bot. Garden, 
607. — 
