PROCEEDINGS OF SOCIETIES. 151 



and well worthy of study, exemplifying in a beautiful manner every gradation of it 

 in almost all the organs of the plant, from the mere simple renate division of the 

 frond, up to the extreme forms of division recorded on the last day. To-night I 

 propose to conclude the subject, by considering the analogies of the remaining 

 abnormal forms of Filices. 



Since I first attempted this arrangement, so many additional species of these have 

 been brought forward, that without any difficulty we can accomplish a division only 

 hinted at then — viz., separate them into four classes — i.e., two varieties and two 

 subvarieties, instead of one of each. For these I intend to suggest names other 

 from those used on that occasion, as there were many objections to the names then 

 used. The first, comprised under my old name Cambricum, I mean to call Dis- 

 sectum, the subvariety I call Sinuatum still, but limit its definition : Dissectum 

 variety ; frond generally more developed than normal ; edges both primary and 

 secondary, crenately or irregularly lobed and symmetrical ; segments rounded at ends ; 

 their edges curled, and crisped, and confluent ; generally barren ; nervures terminat- 

 ing within leafy expansion and distinct throughout their whole course. Examples 

 — As Trichomanes, var. incisum; Cten. vulgare, var. Cambricum (Linn.). (This 

 division includes so much of my variety Cambricum as had the parts of the plant 

 in excess.) Sinuatum, subvar. ; frond mostly more luxuriant than normal; seg- 

 ments irregularly lobed and serrated, pointed, and distinct, generally unsymmetrical; 

 outline pointed and distinct ; fruitful ; nervures terminating within leafy expan- 

 sion. Examples — As Trichomanes, subvar. Sinuatum (Mei) ; Cten vulgare, var. 

 Hibernicum or Mackaii (Auct.). These forms are essentially modifications of a 

 secondary axis (generally the veins and venules, which we find multiplied and di- 

 vided, but not symmetrically as a whole), and consists in the excessive unsymme- 

 trical development of some one or other. It is often difficult to separate this variety 

 from the variety Ramosum (Cristatum), especially in simple fronds ; but we have a 

 valuable guide in one character which prevails almost through the entire — the barren- 

 ness of the frond — a character so universal in the class, it might almost be adopted as 

 distinctive. In some species this may be explained by the modification the veins 

 undergo ; the vein, which should be merely forked and bear the spore case, becoming 

 branched and barren, as is seen in Ctenopteris vulgare. The number of species in 

 which it is found is rather limited, though, doubtless, if investigation be made, 

 others will turn up. The subvariety is fertile, the same modification not taking 

 place in the venation. There is a great latitude of modifications in the forms com- 

 posed under Sinuatum, from the simple irregularly crenate frond up to divisions 

 as well marked as those with which you are familiar in the Polypodium 

 cambricum of Linnaeus. Under this group we find an illustration of a previous ob- 

 servation, that a subvariety and a variety are sometimes found in accidental com- 

 bination, with this limit, that, as far as I know, the parallel subgroups are never 

 found so. For example, you will find variety Dissectum in combination with sub- 

 variety Multifidum, but never Dissectum in combination with Sinuatum, or Ramo- 

 sum (Cristatum) in combination with Multifidum. How far varieties combine with 

 one another I am not prepared to state.* The next subgroup comprises the latter 

 portion of my old Cambricum, or that in which the parts of the original type are 

 found contracted. For this and its subvariety it is proposed to use the names 

 Laciniatum and Truncatum — both names suggested to me by Mr. Wollaston. 

 They consist essentially in the absence of some organ or part of the plant, 

 and bear the following definition: — Laciniatum, variety; frond less developed 

 than normal, often reduced to a mere midrib ; pinnae and pinnules con- 

 tracted, often reduced to a mere line, or absent ; epidermis, normal or puckered, 

 sinuated and thickened at its margins, often ending in a hem within the 

 edge of the frond ; edges of the frond generally waved and cut ; nervures ge- 

 nerally produced beyond, or else terminating abruptly in the margin of the leafy 

 expansion ; outline linear, not curled or crisped ; "veins often very irregular in 



* The varieties are found combined with one another, The following are examples— Vars. 

 Cristatum and Laciniatum, in Ath Filix Faemina R. Gunning's variety. The same vars. in Phyl. 

 Scolopendrium Guernsey form, but vide list. Subvarieties obey the same law— ex. gr., Lophodium 

 Filix mas. Ramosum (Wol.) is subvar. multifidum combined with subvar. sinuatum, <fcc. 



