512 



JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



two years since they were divided, are yet without fronds. It 

 seems probable that the male organs may be on the one portion 

 and the females on another ; hence the absence of fronds. Plants 

 raised from a split prothallus are not, however, always alike ; 

 occasionally they are strikingly distinct, though mostly bearing 

 a resemblance to each other. 



Increased or diminished development in fronds, pinna?, or 

 pinnules in endless directions will eventually add enormously to 

 the varieties cultivated. The energies are often expended in 

 certain directions. A large capitate head may be at the expense 

 of the tassels of the pinna?, or large tasselled pinna? at the 

 expense of the capitate head. A w T ell-developed plumose form 

 is more or less sterile ; the energy is directed in subdivision, 

 and in consequence the texture is thinner, and there does not 

 appear to be sufficient strength left to produce spores. On rare 

 occasions there is a thickening in this texture on parts of the 

 frond, and there sori are formed. In the case of the plumose 

 form of the Hart's-tongue known as crisjpum, occasionally a 

 number of plants, all sterile, are found in close proximity ; the 

 late Colonel Jones found twenty-nine near Shirenewton, and 

 Major Cowburn has found nineteen at Deimil Hill. Marvellous 

 wild finds are usually solitary examples. The Neplirodium 

 imleaceum var. cristatum found in the West of England was a 

 single specimen, and no second example has been discovered ; 

 yet a somewhat similar form has more recently, however, been 

 found in North Wales, the two differing in .the one being flat- 

 crested and the other bunch-crested. 



An increase in the strength of a plumose form would thicken 

 the texture of the frond, and enable it to bear spores. 

 Experiments have been tried on flowering plants as well as on 

 Ferns, in the hope of procuring this strengthening result. 

 Taking into consideration that a vast number of antheridia are 

 requisite to fertilise a plant, the single Dahlia was selected as 

 the flowering example, and capitate forms of Aspidium angulare 

 as the Fern to be experimented upon. As it was wished to use 

 six times as much pollen of a white Dahlia as that of a pink one, 

 six small brushes were filled with the pollen of a white flower, 

 and one from that which was pink, the whole b2ing collected on a 

 larger brush and then repeatedly applied to a white flower. 

 The result in the seedlings was 87 per cent, of white flowers ; 



