FERN CROSSING AND HYBRIDISING. 297 
have, however, framed my paper 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 recognise their value in 
the direction I have endeavoured to indicate. 
In conclusion I may mention that there is one point in connection 
with Fern crossing which has no parallel in flowering plants, and that 
is the possibility of attempts being frustrated by apogamy. In nume- 
rous 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 falcatwm, 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 has been found, I sowed Cyrtomiuwm falcatum and C. Fortunew 
thickly with L. p.-mas cristata, obtaining a pure crop of both; a result 
I should have expected had I 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 num- 
ber of varieties of Lastrea p.-mas which afford extremely strong evidence 
of crossing, and I am therefore inclined to believe that apogamy in the 
species is by no means without exceptions, and that normal sexual repro- 
duction frequently occurs. 
Thanks to Mr. Alex. Wright, of South psn I am able to present 
photographs of several of the crosses exhibited, viz. 
Fig. 107. Lastrea dil. lepidota x L. d. oristata. 
Fig. 108. Polypodiwm vulgare, var. bifido-cristatum x P. v. var. elegan- 
tissimum. 
Fig. 109. Polystichum angulare, var. polydactyla x P.. ang. lineare. 
N.B.—In this cross the defective polydactylism alluded to in the paper 
is seen and indicated by crosses. 
Fig. 110. P. angulare, var. rotundatum x P. ang. cruciatum. N.B.— 
The rounded pinnules are not well shown in photo, but the normal out- 
line of the lower part of the cruciate parent is preserved clearly in the 
Cross. 
Fig, 111. Scol. vulg. var. crispwm fertile x S. v. muricatum. Result, 
a muricate crispum. Athyrium filix femina, var. congestum x A.f.f. var. 
excurrens. Result, a congested excurrens ; a very striking cross; the hair- 
like terminal points of B and of A+B are hardly visible in the illustration. 
