288 
ON THE VALUE OF PLATES AND ILLUSTRATIONS. 
Aspidium dilatatum. 
A. spinulosum, /3, Brit. Flo. (Hook.), 3rd Ed., p. 451 ; 4th Ed., 386. 
A. dilatatum, Brit. Bot ., With. (MacGilliv.), p. 381. 
“ “ Brit. Ferns and Allies (Francis), p. 35, pi. 2, figs. 12, 13. 
Polipodium cristatum, Fil. Brit. (Bolt.), p. 42, tab. 23. 
Under any circumstances it would be no easy task to describe and distinguish 
the permanent varieties of this extremely variable plant; I myself feel it pecu¬ 
liarly difficult, having not more than a dozen specimens for reference, and having 
only examined it in one district; I will, however, attempt it as far as my 
observations will allow, hoping that those whose opportunities are superior, or 
whose sphere of observation is more extensive, will freely and kindly correct me 
should I have erred in this or any other point. 
as. dilatatum-vevum. Frond triangular, ovate, sub-tripinnate; height from 12 
to 20 inches; light green, flat; pinnules oblongo-ovate, lobes sometimes convex. 
(Nearly A. spinulosum of Hooker, &c.) 
/3. (dumetorum? ). Frond ovato-triangular; height from 4 to 14 inches, more 
or less drooping; pinnules oblong, rather light, and bright green; fertile in all 
sizes. 
y. ( dilatatum , Auct.). Fronds triangulari-ovate; height one to three feet, 
tri-pinnate, dark green, drooping; a most beautiful and graceful variety. 
I have never yet seen the variety 5 (rejlexum, Bree), but should think it 
has an equal claim to rank as such with the others, respecting which I am yet in 
much doubt. 
Bewsey House, Warrington , T. G. R. R. 
Jan. 12, 1839. 
( To be continued.) 
ON THE VALUE OF PLATES AND ILLUSTRATIONS AS SUBSER¬ 
VIENT TO THE STUDY OF NATURAL HISTORY. 
By Edwin Lees, F.L.S., &c. 
“ The image of it gives me content already.” 
Shakspere’s Measure for Measure. 
In a former number of The Naturalist I think I recollect an observation of Mr. 
Rylands (for whose entomological acquirements, as instanced in various articles, 
I entertain great respect) deprecatory of the employment of plates as subservient 
auxiliaries in the study of Natural History. At all events his remarks were 
