288 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
FERN CROSSING AND HYBRIDISING. 
By Caas. T. Drusry, F.L.8., V.M.H. 
Tue absolutely microscopic nature of the organs which, in Ferns, 
perform the part of flowers renders their systematic crossing or 
hybridising an extremely difficult matter, and, humanly speaking, it is 
impossible to proceed with two Ferns, with the same certainty of 
knowledge that the preliminary steps are sure and indubitable, as the 
florist can with two distinct flowers. In the one case he deals with 
something he can see and handle: he can take his scissors and remove 
the stamens before the pollen is ripe, and in other ways secure a virgin 
flower on the one hand, while to remove the pollen from another set of 
stamens on another plant is the simplest matter imaginable. With both 
individuals he starts on a clear and definite basis, and with ordinary 
precautions against intrusive insects, &e. can practically swear when the 
seed-pod swells that it contains A plus B. With the Fern, however, it 
is quite another matter. HKven though we gather a fertile frond of a 
known variety, and isolate it by placing it between clean paper in the 
dwelling-house, the chance of stray spores from other Ferns having been 
shed upon that frond beforehand is always existent. Uncertainty No. 1. 
Assuming, however, that a pure culture is obtained, the prothall grow 
profusely and healthily, but when their time for fruition is near we can 
only discern, and that moreover upon their undersides, even with a good 
lens, a number of tiny pimples, some spherical and some oblong. A pin’s 
head would accommodate a dozen of either sort. Within the round 
ones are packed a score or two of little tadpole-shaped organisms, only 
visible under a high-powered microscope; and at the bottom of the 
oblong ones is an embryo seed a few degrees bigger. ‘These are the 
elements the Fern crosser has to deal with, and to carry out his ideal 
he should carefully lift one of these tadpole bodies just when it bursts its 
round-headed container and starts on its wedding journey across the 
ocean of a dewdrop, and then carefully convey it to another and distant 
bride selected for it, in lieu of the maiden close at hand. Meanwhile it 
is fairly certain that that other bride has many other suitors, and the 
new one may consequently arrive the day after the wedding, when, of 
course, the match-maker is frustrated. He is frustrated, but how is he 
to know it? To come back to botanical phraseology, he may even have 
isolated the archegonium of one prothallus by severance, but as there is 
no doubt whatever that cross-fertilisation occurs through the myriad tiny 
insects that are invariably present, even then there is a risk, and in fact 
the risks, difficulties, and uncertainties are practically so unavoidable that 
a different method altogether is compulsorily adopted. The usual course 
when a cross between two distinct Ferns is desired is simply to collect 
the spores of each as carefully as possible with a view to eliminate strays, 
and then either to mix them intimately before sowing, which is the 
better plan, or sow them one after another rather thickly in the same 
pan. By this means a proportion of the distinct spores are bound to 
