26 FERN GROWING 



soil, a more favourable situation, and greater attention are 

 sufficient reasons. 



" At the Dundee Meeting of the British Association in 

 1867, it was pointed out that a certain law of form in the 

 varieties of Ferns seemed to be common to all species — 

 crested, branched, revolved, truncated, tortuose, brachiate, 

 plumose, cruciate, linear, or depauperate, in both fronds, 

 pinnae and pinnules — and the manner of these changes are 

 common to all the species, and even the multiple of these, 

 the combination of several characters, such as the linear- 

 crested or cruciate-crested. In course of time we may 

 produce plants having many of these forms combined on 

 the same frond. 



" Again, spores gathered from an abnormal portion of a 

 frond can reproduce this abnormality, whilst spores from a 

 normal portion of the same frond can produce normal plants. 

 Also, if plants are raised from varieties for several generations, 

 it is almost impossible to obtain the original normal forms. 



" The spores from crossed varieties are quite as proliferous 

 as that of the normal form, whilst hybrids — i.e., crossed 

 species — are all but sterile. There appears to be no abso- 

 lute sterility. Take the hybrids that were raised between the 

 Aspidiums aculeatum and angulare. A hundred pans of spores 

 that were sown did not produce a single plant. Mr. Carbonell, 

 however, raised nine, and Mr. Barnes thirty plants,* all of 

 which differ from the parents and hybrids, the grandchildren 

 being mostly congested in growth. With regard to Nephrodium 

 remotum, a hybrid between spinulosum and Filix-mas, repeated 

 sowing of spores for more than ten years did not produce 

 a single plant, though by accident Dr. Stansfield once 

 succeeded. 



"At the British Association Meeting in 1870, the author 

 gave the following additional results : — 



* Half of Mr. Barnes's seedlings had nothing to do with the spores sown. 



