32 FERN GROWING 



"One of his more recent experiments was the endeavour 

 to ascertain whether more than one plant could be produced 

 from a single prothallus. It had been noticed over and over 

 again that in trying to separate seedlings into single plants, 

 it often occurred that some were so closely connected that it 

 required great skill in separating them. When these grew 

 to maturity, most of them were seen to resemble each other, 

 and probably had sprung from one prothallus, and this was 

 well seen, more especially in three plants of a very distinct 

 variety copying each other. 



" Four years ago he transplanted spores very thinly so as 

 to allow them room to expand. When these prothalli were 

 fully grown, a number were cut with a sharp knife into two, 

 three, and four pieces, and replanted ; and those simply cut 

 into two produced two plants, but when divided into four 

 they have not produced fronds ; they have increased in size, 

 and though it is more than two years since they were divided, 

 are yet without fronds.* It seems certain that the male 

 organs must be on one portion and the females on another ; 

 hence the absence of fronds. 



" Increased or diminished development in fronds, pinnae, 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 pinnae, or large tasselled pinnae 

 at the expense of the capitate head. A well-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, t 



* Now more than six years ago, and three of the prothalli are as yet alive but still 

 without fronds. 



t The A. angular e var. Baldwini has this year become sparingly soriferous ; 

 the sori are few in number, almost solitary, and there is no indusium. 



