162 
BRITISH FERNS. 
variety “cristata,” a grandiceps form. Even by apospory (i.e., 
prothalli formed directly on the frond, without the intermediate 
spore,) varieties are produced ; and in the case of those from 
“ Clarissima ” (of the Lady fern) we may instance a subplumose 
form, a flexuose-pinnuled one, and another that is furcate and 
flexuose. 
There is a peculiar connecting link between one species and 
another, for there is a mimical power that gives crested, branched, 
cruciate, and in short increased or diminished development in 
fronds, pinnae, and pinnules, so that these characters are found 
almost identical in many species. Again, a well-developed variety 
may (as example) have a crested peculiarity in which the pinnae 
copy the whole frond, and even the pinnules imitate the pinnae. 
Variegation can also be obtained by crossing. The late Colonel 
Jones exhibited a striking example in Aspidium angulare : having 
added the polydactylous character to a multilobe, he then succeeded 
in making it variegated by a second cross ; whilst in Scolopendrium 
vulgare I have obtained a dozen variegated forms. 
The usual method of raising varieties is the one pointed out by 
me in 1867 ; but more recent experiments have shown that we can 
go beyond this. In 1888 experiments were made, based on the 
notion that it required a swarm of antheridia to make the 
archegonia fertile. I had formed this opinion partly by what I 
had learned from Dr. Hudson on microscopic animal life, and 
partly on what I had done in crossing Dahlias. In the latter case, 
if I filled half a dozen small brushes with the pollen of a white 
Dahlia, and one with that from a coloured flower, and mixed these 
together (in the proportion of 6 to 1) and then impregnated a white 
flower, there was 87 per cent, of white seedlings, whilst if the pro- 
cess were reversed, i.e., six times as much pollen from coloured 
flowers, white was almost absent in the seedlings.* To get a 
certain desired colour, moist paints were mixed together in various 
proportions of white and colour ; and this was imitated with so 
many brushes full of white pollen to one of the colour selected. 
This could not, however, be done with ferns ; but certain proportions 
in bulk of spores from a crested Nephrodium paleaceum and of an 
uncrested variegated Nephrodium Filix-mas were sown together, 
and the plants (500 in number) though yet too small to exhibit 
variegation, are large enough to be crested, and every one of the 
plants is crested. If, therefore, it be desired to produce heavily- 
crested ferns, and at the same time to increase the size of the 
variety without reducing the crests ; to make any alteration in 
form that shall not be at the expense of these crests, it is recom- 
mended that a much larger proportion of the spores of the crested 
than of the other form shall be sown together. 
* As an experiment, in 1889 pollen was used from different genera and 
species ; the seedlings have bloomed, and are like the seed-bearer. The 
pollen was apparently able to give life to the seed, but not to show any of the 
characters of the male. 
