FERN CROSSING AND HYBRIDIZING 39 



field for combination, as well as our marvellous Polystichums, of 

 which the best plumose divisilobes are often sufficiently fertile to 

 afford material. P. setosum especially should be tried with some 

 of the best. Could thorough alliances be effected between this lovely 

 lucent hard-fronded evergreen Shield Fern and such gems as P. a. 

 cristatum (Wollaston No. 10) , P. a. cristato-gracile, Moly, and some 

 of the divisilobe plumosums of Jones and Fox, Pearson and Esplan, 

 the results could only be gems of first water. Then there are our 

 Osmunda regalis and Osmunda japonica cristata to act as suitors to 

 0. cinnamomea, 0. interrupta, and 0. gracilis, and finally there are 

 our lovely forms of Polypodium vulgare, P. v. cristatum, grandiceps, 

 Fox, Forster, and Parker, bifido-cristatum, and pulcherrimum , to 

 say nothing of P. v. elegantissimum, the British-born parent of P. 

 Schneiderii, all waiting for chances of the introduction which they 

 certainly merit to the aristocratic Fern circles of their more stately 

 foreign relatives. The field indeed is all but virgin, and we are con- 

 fident that careful cultivation of it would yield a host of new and 

 charming novelties, provided — always provided — that it be done 

 on right lines. 



Into the question of simple crosses between varieties we do not 

 propose to enter, space prohibiting, though to us and to British 

 Fern specialists generally there is a wide and fertile field still but 

 partly cultivated. We have, however, framed our chapter rather 

 for the benefit of the more numerous raisers of exotics, who are too 

 apt to ignore the merits of our home Ferns altogether, and only here 

 and there recognize their value in the direction we have endeavoured 

 to indicate. 



In conclusion we may mention that there is one point in connec- 

 tion with Fern crossing which has no parallel in flowering plants, 

 and that is the possibility of attempts being frustrated by apogamy. 

 In numerous Ferns it has been found that the young plants are 

 asexually generated in the prothallus, a simple bud arising on the 

 spot usually occupied by archegonia. Pteris cretica, Lastrea pseudo- 

 mas cristata, Cyrtomium falcatum, and others present this peculiarity 

 in nearly every case, and of course under such circumstances no 

 crossing is possible, unless in exceptional cases, where the normal 

 process may obtain. As Cyrtomium and Lastrea, for instance, are 

 closely related, and no crested Cyrtomium had been found, we sowed 

 Cyrtomium falcatum and C. fortuneii thickly withL. p.-mas cristata, 

 obtaining a pure crop of both, a result we should have expected 

 had we not forgotten the apogamous character of both members 

 of the desired alliance. This, then, constitutes a hidden hindrance 

 peculiar to Fern crossing. There are, however, a number of varieties 

 of Lastrea p.-mas which afford extremely strong evidence of crossing, 

 and we are therefore inclined to believe that apogamy in the species 

 is by no means without exceptions, and that normal sexual repro- 

 duction frequently occurs. 



