THE LIFE HISTORY OF FERNS 17 



(Figs. 2, 3, 4, 5, 6, 7), and which explain themselves in the light 

 of our description. 



We thus see that while (£he life cycle of a flowering plant is seed, 

 plant, flower, and seed again, that (of a Fern is spore, prothallus, 

 antheridia, archegonia, embryo-seed, and fern) an intermediate 

 stage, the prothallus, being thus interposed between spore and 

 fern to provide for the reproductive system existent in the flower, 

 but not in the Fern proper, and which, as a general rule, is essential 

 in all the higher organized plants and animals for their continued 

 existence. Nature, however, is not content with pursuing always the 

 same lines, and, as is peculiarly evidenced in our native Ferns, is apt 

 to depart from the normal or usual ones, and not only to vary her 

 plans of structure on very wonderful lines, as this work demon- 

 strates, but also to vary her modes of reproduction, and in this 

 direction it is a remarkable fact that the study of the abnormal 

 forms, i.e. the wild " sports " of British Ferns, has, in the hands of 

 eminent scientific investigators, proved that the normal life cycle 

 can be, and has been, varied in every possible way. In point of 

 fact, every one of the stages of the life cycle above indicated has 

 been proved to be needless to secure continuance of the race, as 

 we will now demonstrate. In the earliest days, when these wild 

 " sports " were discovered, they were stigmatised by scientific 

 botanists as " monstrosities," and being regarded in the light of 

 mistakes on the part of Nature, were entirely ignored as subjects 

 for study. In the early eighties, however, the writer having been 

 fortunate enough to discover an entirely fresh form of Fern repro- 

 duction (apospory), of which some particulars are given below, 

 he advanced the opinion that Nature was far more likely to betray 

 her secrets in her abnormalities or divergences from the beaten 

 track than in her normal productions, and this led to investigation 

 by Professor F. O. Bower of the Glasgow University, and eventually 

 by others, of a number of British Fern varieties, with the astounding 

 result that it was found that : 



1. The spore was needless, as the fern frond was capable of 

 producing prothalli by direct outgrowth (apospory 1 ), either 

 by transmutation of spore-producing energy and consequent 

 transformation of aborted spore capsules into prothalli on the 

 sites of the spore heaps (soral apospory), or by mere outgrowths 

 of the terminals of the frond divisions into true prothalli (apical 

 apospory, discovered by Mr. G. B. Wollaston, of Chislehurst). 

 Dr. F. W. Stansfield also demonstrated that apospory could be 

 induced by close treatment from the crests of a Lady Fern, a very 

 curious case. 2 



1 Professor F. O. Bower, F.L.s., on "Apospory and Allied Phenomena," Linn. 

 Trans., vol. 2, part xiv. July, 1887. 



2 Dr. F. W. Stansfield, on "The Production of Apospory by Environment in 

 A.f.f. uncoglomcratum. Journal Linn. Soc, vol. 34, No. 227, pp. 262-7. 



