DXTBUW KATUBAL HI8T0BT 80CTETT. 49 



either smaller or larger than original type ; pinnae serrated, or irregularly lobed 

 at their edges; outline rounded; segments rounded and confluent. This in- 

 cludes two almost distinct types, in one of which we find the parts of the origi- 

 nal type in excess, in the other we find them contracted ; this last corresponds 

 to strictum. Sinuatum — Pinna serrated and irregularly lobed ; segments 

 pointed and distinct ; frond generally more luxuriant than normal. 



Sub-forms, owing to a difficulty in procuring specimens, I have not been as 

 successful in reducing to classes, though, that it can be done, 1 doubtnot. I shall 

 content myself, therefore, with laving one before you, which 1 propose to call 

 Abbreyiatiim, taking as its type the form of the male fern to which that name 

 has been given. This we find represented in the following species, and define as 

 follows: — Abbreviatum. Sub-form, frond contracted ^nallits parts regularly, the 

 pointed outline of the frond retained. Examples : Polypody of the oak ; sub- 

 form, Acutum (Newman), Youghal. Male shield fern; sub-form, Abbrevia- 

 tum (Moore), England. Prickly shield fern ; sub-form, Lonchitoides, Clare and 

 Ulster. Angular-lobed shield fern ; sub-form, Abbreviatum (mihi), county of 

 Wicklow. Wall rue, spleenwort; sub-form, Abbreviatum (mihi), county of 

 Clare Hart's tongue, sub-form, Angustifolia (Auct), Killaloe. Lady fern, 

 sub-form, Abbreviatum (mihi), Ardmore. I doubt not but other forms might 

 be referred to this class, ex, gr. : brittle bladder fern, var. dentata, &c., but suf- 

 ficient are quoted to show what 1 mean. This, Gentlemen, is a general outline 

 of the system proposed to be introduced — that it is not an unnecessary one will 

 b» evident, if we consider the number of those varieties which every day's re- 

 search brings to light, and the consequent number of descriptions which must 

 be introduced for them into our Floras, the greater part of which may be 

 avoided by pursuing the plan now sketched out. I think the same plan might 

 be pursued in general botany with a good effect ; but it is of far greater impor- 

 tance in filicology, as so many of this class of plants may be recognised by their 

 external form alone. Concerning the study of varieties, a few words in conclu- 

 sion. I know it has been urged as an argument against it, that it tends to in- 

 crease spurious species, but this statement is an error, as the eflTect of it would 

 be quite the other way, as nothing can tend so much to do away with spurious 

 species as a study of all the changes species undergo. In the kindred science 

 of zoology, when we are in doubt about points of economy, we seek them often 

 not in the perfect animal, but in the monster. Why then should we not in plants 

 apply the same rule, and seek amidst the vagaries of monstrosities for the rules 

 which govern regular forms? for thence can they often be deduced, as by the 

 breach of the law we oftentimes are reminded of its existence. To show that 

 this theory, system, or whatever you will call it, is not unnatural, 1 have drawn 

 out a table of eight species, in which we find these forms now described prevail- 

 ing in the following ratio : — The species are, male fern, hart's tongue, common 

 polypody, northern hard fern, lady fern, maiden's hair, spleenwort, angular 

 shield fern, and prickly shield fern. Amongst those, Ramosum occurs in the first 

 four, Multifidum in the whole eight, Cambricum in the first four, and the sixth, 

 i. e., in five, Sinuatum in the same five, and the sub-form Abbreviatum, in the 

 first, second, third, fifth, seventh, and eighth— six in all. This, Gentlemen, con- 

 cludes the subject. Whether my deductions are over-drawn or not, you can judge 

 for yourselves, as you have before you the greater part of the specimens from 

 which, as the materials, they were drawn. Alany of these, however, especially 

 among the sub-forms, are now very inadequate pictures of what they were when 

 growing, as it is impossible, even by the most careful drying, to preserve many 

 points of importance in distinguishing between the forms. They are all, with 

 very few exceptions, which I have marked, Irish specimens, gathered during the 

 last two years, and, therefore, fair specimens of the forms to be found in a state 

 of nature. 



