THE CEOSSINC! OF FEENS. 



349 



raised accidentally about a dozen plants of P. acnleatum, in 

 which the peculiar cresting of the angulare in question was 

 reproduced, in an unmistakable manner — the crossing having 

 evidently been efl^cted by stray spores from an almost 

 normal plant of P. aculeatum, growing in close proximity 

 with the plant from which the spores had been gathered ; 

 and I myself raised two plants in which the polydactylous 

 cresting of an angulare reappeared in a decided aculeatum — 

 a polydactylous aculeatum having been previously unknown. 

 Nor should Mr. Stabler's remarkable Lastrea (so well 

 known as l^j. f. mas Stableri) bo i)as8ed over here ; it has 

 been universally regarded by fernists as a cross between two 

 species of the male fern, the marked character of L. f. mas 

 Barnesii being transferred to the more solid substance of 

 I,, ps. mas. It is easily ropi'oducod from spores. 



Cross-beeeding, 



So far the crossing of species, or hybridization })roper. I 

 will now take a few of the most marked instances of the 

 crossing of varieties, nor will I mention any with regard to 

 which doubt could be likely to arise in any reasonable mind, 

 and I will not confine the instances to any one species. 



Years ago, returning from a successful hunt, Mr. Barnes 

 thought he would put to the test the suspicions regarding 

 the crossing of ferns, of which he could not rid his min'd ; 

 he accordingly chose two of the most marked forms of Las- 

 trea propinqua, both of his own finding— (1) a truncate form, 

 whose claim to distinction lay in the entire deficiency of 

 the upper part of the frond (to the extent of about a third) ; 

 (2) a very symmetrical crested form, the best of its class — 

 L. p. cristata of Barnes. Spores of these were sown together, 

 and the result was, I should think, sufficiently conclusive- 

 one plant being an exact reproduction of the truncate form 



