TRANSACTIONS OP THE SECTIONS. 91 



The Abnormal forms of Ferns. Bij E. J. Lowe, F.R.S., F.L.S., F.G.S. 



The following facts have come under the aiithor's notice during the series of inves- 

 tigations on this interesting subject. 



1st. As regards the various aljnormal forms that species will assume. It is a 

 singular fact that most of our British ferns put on ajjpearances closely in imitation 

 of each other, that the varieties of each species have nianv characters in common, 

 and that a certain law of form of variety seems- to extend more or less through 

 both British and exotic species. The more usual forms running through nearly 

 all our British ferns are those having the fronds crested, crisp, imbricated, confluent, 

 corymbiferoHs, muUifld, acuminate, narrow, plumose, interrupted, depauperate, ramose, 

 lind dwarf ; and not only this, but we have the multiple of these, or the combining 

 together of two or three characters in one frond, such as the 7iarrotc-crispcd, the 

 mtdti/ld-crisped, or the ?iarrow-muUi/id, as examples. 



Most of these abnormal varieties have been been found wild, and a large propor- 

 tion in localities where the species is neither abundant nor luxuriant in growth. 

 Of course, springing from an individual plant, it occupies time and care in raising 

 duplicates from spores ; and in doing lliis, singular accidental sports have been 

 raised and a new method of obtnining varieties detected. 



2nd. As regards the gathering and sowing the spores of these sports. It seems 

 from these experiments almost an established fact that spores gathered from one 

 portion of an abnormal frond will produce different varieties fior.i those of spores 

 gathered from another portion of the same frond; that if an accidental abnormal 

 frond, or jDortion of a frond be fertile, it is not impossible to reproduce from its 

 spores plants having fronds in imitation of the accidental abnormal form. 



If hj cultural means we can induce the growth of singular fronds, we are very 

 likely to perpetuate the variation of form from the spores. B3' removing the 

 drainage from the roots of plants that had completed their autumnal growth and 

 inducing an unnatural and sickly condition for several months, and only repotting 

 and giving a generous treatment when the fronds were almost ready to unfold, this 

 caused them to produce abnormal fronds in both the British and exotic species. 



3rd. Our knowledge of the reproductive organs of ferns is obscure, and it has 

 been said that the iein As})lenium micrudun is a hj'brid between ^i«/j/e«»n« marinum 

 and Asplenium lanceolatum, that Lastrea remota is a hybrid between Lastrea spinu- 

 losa and Lastrea flli.r-mas, and perhaps that Asplenium f/ermanicum is a hvbrid 

 between Asplenium septentrionale and Asplenium ruta-miiraria. Now it doe's not 

 appear tliat these ferns have e^ser been reproduced from their spores ; and therefore 

 ( if we may accept these a? hybrids) that hybrids of species are unproductive, ^vhereas 

 the varieties raised from a species can readily be reproduced by spores. 



On some Points in the Anatomif of the Thysanura. 

 By Sir J. Lubbock, Bart., F.B.S., Pres. Ent. Soc. ^r. 

 The author remarked that the Thj'sanura, though extremely numerous, and in 

 many cases very pretty little creatures, liad attracted but little attention, owing, 

 perhaps, to their great delicacy and the consequent difficulty of preserving them in 

 a satisfactory condition. Under any decaying log of wood, under damp leaves, in 

 long grass, in short, in almost any damp situation, the Thysanura form no small pro- 

 portion of tlie population. Like other insects, they have six legs, but they never 

 acquire wings. I'he tail is generally provi-.Ied with two long appendages, which 

 are bent forward under the br.ciy, and thus form a spring, by means of which the 

 animal is enabled to jump with great activity. A Smynt/iurus, for instance, mea- 

 suring one-tenth of an inch in diameter, will easily jump up twelve inches in the 

 air. This, however, is due mainly, not to muscular power, but to the elasticity of 



II. In Proceedings of Eoyal Society of Edinburgh, vol. iv. p. 174, "Spermogonia and 

 Pyenidia of the Higher Lichens." 



III. In Tr;uisactions of Linnean Society of London, vol. xsv. p. 493, " New Zealand 

 Lichens."' 



IV. In Journal of Linnean Society of Loudon, vol. ix. p. 268, Arthonia melaspermcUa. 



V. In Quarterly Journal of Microscopical Science, Janviary 1857, Ahrothallv.s. 



