124 



THE BOOK OF CHOICE FERNS. 



The above remarks naturally bring us to a subject which for some con- 

 siderable time has given rise to much controversy, but which, owing to the 

 better knowledge of the reproductive organs, and of their functions as bearing 

 on the fecundation of the spore, is now admittedly beyond dispute. We refer 

 to "Hybridisation." On account of the minute nature of the phenomena 

 observable in fertilisation in Ferns, systematic hybridisation as in plants 

 provided with flowers, and consequently with visible organs, may be at once 

 discarded as impracticable. But the fact remains that the sowing of spores 

 of several varieties together often results in offspring of mixed character- 

 istics, proving that crossing really takes place. In several of the cases of 

 the above-named garden hybrids, for instance, none of which are known for 

 certain to be the result of forethought, a connection between the two parents 

 is clearly shown; and this is still better exemplified in some of the results 

 of intentional crosses produced by several of our British Fern growers. It is 

 particularly the case with plants raised by Mr. Lowe, Mr. Clapham, Colonel 

 Jones, and others, who have made this highly interesting operation a subject 

 for special study, to which their untiring attentions have been devoted, with 

 the results that Ferns are now produced, as examples of success in fertilisation, 

 being crosses that possess characters combining those of specially fine varieties 

 of which they are offspring. Among the most striking instances illustrative 

 of satisfactory results in intentional crossing, that mentioned in Mr. Druery's 

 book on "Choice British Ferns" (p. 44) as being Mr. Clapham's greatest 

 success, and the result of a cross between a beautifully-crested Polypody 

 (Polypodium vulgar e bifido-cristatum) and a very finely-divided one (P. elegan- 

 tissimum), is particularly remarkable and conclusive. In this case, the result 

 is the transference not only of the characteristic cresting of the former to 

 the latter, but also of its peculiarities to the otherwise normal fronds, which 

 the latter is in the habit of producing occasionally — a feature which, of course, 

 places the cross beyond a doubt. 



It does not, however, follow that operations of this kind are always 

 successful, and failure at a first experiment must not prevent another attempt. 

 With a view to ascertaining the practicability of this mode of producing 

 new forms, we personally undertook the sowing, on a very large scale, of 

 spores of all the known species and varieties of Osmunda, considering 

 that on account of the very distinct forms which it contains, that genus was 



