126 NOTICES OF BOOKS. 



have been already favourably noticed by us. The 10th Fasciculus 

 commences with Tab. XXIX., Lastrea Thelypteris, which is very well 

 represented. In the next, Plate XXX., the thickened stem and the 

 copious fructifications of AtJiyrimn Filix-fcemina render the figure very 

 defective. This is acknowledged to be a cultivated specimen, and we 

 should not consider it by any means a sample of the normal form of 

 this species, — its^f indeed very variable, as may be seen in the four fol- 

 lowing plates, where no less than eight varieties or forms are given, so 

 different in aspect that one only wonders species-makers are not more 

 united in considering several of these specifically distinct species, for it 

 might be done with as much reason as in the dilatata group. Happily 

 our author, in practice at least, takes a more correct view of things ; and 

 he very properly too places the four last of these eight states under the 

 head of "(permanent?) monstrous forms," especially the three last (in Tab. 

 XXXIV.), viz. crkpum, depaiiperatum , and dmectum. The history of 

 this well-known Fern occupies no less than twelve of these imperial 

 folio pages, and 31 varieties (!) are named and distinguished. "We 

 must also repeat," the author says, "in order that the truth may ap- 

 pear, that among herbarium specimens, in addition to those we have 

 referred with tolerable certainty to the forms above enumerated, there 

 are many others which could not be satisfactorily placed." It would 

 be a marvel if they could; and he asks and answers the following 

 questions :— " Does this long series of gradations" (that is from the 

 normal form to absolute monstrosities) "represent a species? One 

 can scarcely imagine two compound Ferns more dissimilar than the 

 extreme state of the molle and incisum groups, or the forms represented 

 in our Plates XXX. and XXXI. (7. Or, after all, is there in nature no 

 such thing as a species among plants, but ever-changing varieties, or 

 races of individuals only ? etc. The deep study of Ferns would be 

 scarcely likely to produce a decided negative to this question." Cer- 

 tainly it is possible to study Ferns so as to leave the mind in inextri- 

 cable doubts and difficulties ; but it must be allowed that as far as re- 

 gards the Athyrium Filix-foemina, from the days of Linneeus until now, 

 the majority of botanists have been uniform in their views of the limi- 

 tation of this species. The author next, in Fasciculus 12, comes to 

 the genus AspUnium, and Tab. XXXV. exhibits two species, both rare, 

 or at least not of universal distribution, viz. : 

 1. Asplenium fonlamm, Bernh. (PoHpodiu 



