3G2 IMPROVEMSNT IN TUP: AKRANGEMENT OF FERNS. 



sion by such a violation of it. If the tribes are good, let their cames 

 terroinate, we will say, in inse, and let the real orders or great families, 

 when determined, bear names in acesa. In Berkeley's book we find the 

 proper distinction laid down between the group containing Liverworts 

 and Mosses, and I am persuaded he is right in adding Charales, which 

 had been placed much lower, and that which contains Horsetails, true 

 ferns, and Lycopodials, fully justifying Endlicher's distinction, adopted 

 by Gray, but not noticed by Berkeley, of Anophytes or Anogens from 

 Acrogens. Here also, in treating of the true ferns, the leading groups, 

 which I regard as true natural orders, founded on the condition of the 

 ring- of the sporangium, are fully recognised, whilst the tribes are, as 

 we have seen, derived from Presl's work. 



Before further explaining my views of the arrangement and mutual 

 relations of ferns, it seems proper to give a very concise, but, I hope, 

 intelligible account of that grand discovery, which has altogether altered 

 our conception of the nature of ferns, exhibiting them to us as not 

 being, properly speaking, the real plants, but a secondary growth from 

 the fertilized germ cell, by means of which the effect of the reproductive 

 process is marvellously multiplied, and the original plant in which that 

 process is perfected is very early superseded by a more highly developed 

 form, in which gemmation produces countless sporangia, with their 

 spores prepared for growth. 



It was long a great botanical puzzle to find anything in ferns repre- 

 senting the stamens in higher plants. It was seen that the sporangia 

 represented capsules, and contained spores, a name technically given to 

 bodies capable of growth into a new plant like the parent, yet not, like 

 the seeds of higher plants, enclosing an embryo. These spores obvi- 

 ously resembled those of mosses, which, since Hedwig's time, are known 

 to be the product of fertilization by organs analogous with stamens. 

 Where, then, were the staminodia of ferns ? They were searched for 

 diligently, but in vain, and ingenuity seemed exhausted. It was seen 

 that the growing spore expanded itself into a cellular disk, mistaken by 

 some for a sort of cotyledon, from some point in which the plant grew. 

 At length the microscope was applied to the minute examination of this 

 disk, and on its under surface were found specialised cells, some of them 

 bearing abundance of phytozooids or active sperm cells ; others again 

 being archegonia, single germ cells, so placed at the base of tubular 

 passages built of cells, as to be accessible to the phytozooids, some of 

 which were even seen to enter the tube, so as to come in contact with 



