536 [Proc- B.N.F.C., 



direct towards the archegonia, and Mr. F. O. Bower has 

 observed that they have made their way unmistakably towards 

 simulated archegonia, consisting of minute applications of malic 

 acid to the surface of the prothallus, which points to sensory 

 organs of some sort. It will thus be seen that in the normal 

 development of ferns, the prothallus constitutes a separate 

 generation, and, therefore, it would form an approach to the 

 higher orders of plants did the prothallus spring direct from 

 the parent plant instead of through the mediation of the spore, 

 since the fern would then be the bearer, if not of flowers proper, 

 at least of these homologues. There has lately been observed 

 on some varieties of Athyrium filix fcemina an abnormal growth, 

 which on close examination has revealed the wonderful phenom- 

 enon — viz., the production of the prothallus upon the parent 

 plants without the mediation of the spore — i. e., apospory, and 

 that is what has rendered A. f. f. clarissima so remarkable , 

 since it was upon it that this peculiarity has been first observed. 

 Professor Farlow, in 1874, discovered an abnormal mode of 

 reproduction, called apogamy, which consists in the occasional 

 development of the fern by direct bud growth from the 

 prothallus without the intervention of the fertilising organs, a 

 phenomenon which is quite the converse of apospory ; the fern 

 in the one case growing direct from the prothallus by a simple 

 vegetative process, and in the other the prothallus growing in 

 like manner directly from the parent fern. The discovery of 

 apospory had been preceded by that of sundry other forms of 

 proliferation upon our native Athyrice^ which really led up to 

 it ; and, in 1872, Mr. Druery, in examining a batch of young 

 plants raised from spores, was struck with the appearance of 

 two whitish dots upon the first frond of an Athyrium. On 

 examination by a lens, they were found to be bulbils. This 

 could scarcely be credited, as at that time no proliferous form 

 of Athyrium was known. Pursuing these researches, another 

 form was found, far more proliferous, bearing seven bulbils. 

 Stimulated by this discovery, Mr. Druery was able, in 1883, to 

 record the proliferous character of the Athyrias in the plumose 

 varieties. On examining a large specimen oi A. f. f. plumosum 



