142 PROCEEDINGS OF SOCIETIES. 



Dr. Kinahan then read a paper 



ON THE ABNORMAL FORMS OF FERNS. 



When, on a previous occasion, I called the attention of this Society to the sub- 

 ject of abnormal forms among the ferns, I stated my suspicion that some general 

 law or laws would be found governing them in their entirety, as a class, and 

 thereby enabling us to group them. I then laid before you a sketch of the groups 

 into which, in conformity with these supposed laws, forms might be divided. This 

 scheme, crude at that time, has, thanks to the contributions of specimens by 

 friends, and additional opportunities of examination afforded to myself, since been 

 confirmed in most of its details, so that the following may be set down as esta- 

 blished : — 1st. That the aberrant forms of ferns obey certain fixed laws of form. 

 2nd. In accordance with these laws, that they may be divided into two great 

 groups, bearing certain relations to each other, similar, and yet perfectly distinct. 

 3rd. That these great groups may be subdivided into parallel subgroups, each sub- 

 group in the one representing a subgroup in the other, totally irrespective of 

 generic or specific distinctions. To examine and illustrate these laws will be my 

 task to-night. First, a few words to remove a misapprehension which I find 

 many labour under with regard to former remarks made on this subject. It is not 

 the object of this scheme to establish new species — far from it ; with species, as 

 such, it has nothing to do, solely dealing with the morphology of the plants under 

 consideration, totally irrespective of species or genus. 



These two great classes, as was before stated, possess strong analogies both to 

 one another and within themselves, yet are perfectly distinct, never running into or 

 producing one another, though we may find a group of the one class in accidental 

 combination with one of the other. These two groups, for which I proposed the 

 names, variety, and subvariety, will be found to possess the following distinctive 

 characters : — Variety is universally a permanent aberrant form, affecting all the 

 fronds of the plant — i.e., uniform ; under all circumstances of cultivation preserving 

 its distinctness, and occurring generally in isolated plants ; if fruitful, often pro- 

 ducing its own form. Subvariety, an aberrant form, seldom permanent under 

 cultivation, affecting only a few fronds, often occurring in numerous plants of a 

 district, and from its spores producing the normal form — this is sometimes perma- 

 nent under cultivation, but never uniformly so. The essential difference between 

 these two classes then, in brief, is — variety, a permanent, uniform monstrosity, and 

 subvariety, a monstrosity not necessarily permanent nor uniform — ex. gr., in 

 Lomaria spicant, var. ramosum, every frond each year dichotomously rounded at the 

 apex, while Lorn, spicant, subvar. multifidum, though much resembling it in gene- 

 ral character, has some years all the fronds dichotomous, other years, perhaps, a 

 single frond dichotomous, and other years none at all — in fact, in this the great 

 difference consists between the two divisions ; in the first, the monstrosity depend- 

 ing on some radical change in its nature, once imprinted on the plant is nearly 

 indelibly so, extending often even to the produce of the spores (as we see in some 

 monstrous forms of Athyrium), while in the subvariety, the monstrosity depending 

 on some mere local or climatal influence, is liable to change as these are modified 

 or removed. It is not meant to be asserted that varieties will not sometimes 

 change under cultivation into another seemingly different variety, or that the spores 

 will not produce plants of the normal type, but that this much may be taken as 

 proved — that variety never changes into subvariety, or subvariety into variety; 

 therefore, the statement put forward, to the effect that variety ramosum is but a 

 form of subvariety multifidum, is based on error. Another grand distinction 

 between the two, in a state of nature, is, that seldom or never do we find the variety 

 in more than one or two plants at most, while the subvariety is often found more 

 or less pervading the plants of a district— ex. gr., there is a little stream glen at 

 the base of the greater Sugarloaf, where L. spicant, subvariety multifidum, may 

 always be found, some years every plant bearing fronds more or less divided, in 

 other years you will only get single plants so affected, while the variety ramosum 

 was found affecting only a single plant. The same might be said of the variety 

 ramosum, and subvariety multifidum of Ath. incisum ; and all varieties found in 

 collections will be found to have had their origin from a few isolated plants found 



