June 17, 1886 ] 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
479 
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COMING EVENTS 
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Llnne&n Sooiety at 8 p.m. Brentwood Show (two days). 
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sun 
Trinity Sunday. 
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TU 
Royal Horticultural Society—Frnit and Floral Committees at 11 a.m.; 
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W 
York Floral F6te (three days). [Pelargonium Show. 
PHENOMENA OF VARIATION, WITH SPECIAL 
REFERENCE TO FERNS. 
[A paper read at the Horticultural Club, June 8th, by C. T. Druery,Esq., F.L.S.] 
[N a paper which I had the honour of reading 
here last season upon certain newly discovered 
phenomena of reproduction in Ferns, I confined 
myself mainly to a description of the various 
normal and abnormal methods by which they 
are propagated, and an elucidation of the 
characteristic differences in these respects be¬ 
tween the Filices and the flowering plants. 
With the view of opening a discussion of some¬ 
what wider interest than the study of Ferns alone could do, 
I purpose to-night to dwell especially upon the peculiar 
faculty of variation possessed by Ferns, and the general 
character of such variation, in order to ascertain from the 
discussion which I hope will follow whether this faculty is 
displayed in as great a degree in the other branches of 
botany which may form the special study of my fellow 
members. I therefore start with the hypothesis that Ferns 
are endowed with a greater capacity of sudden variation 
under natural circumstances than other plants. I say under 
natural circumstances, because it is chiefly wild sports which 
I have in view, and not the wonderful differences which 
careful cultivation and selection are capable of effecting in 
almost every living thing if only time enough be granted. 
The faculty of variation is general throughout organic 
life, but in the vast majority of cases the individual diffe¬ 
rences displayed between organisms of the same species are 
mainly the result of different conditions of growth, and do 
not involve any material alteration of structural plan. The 
offspring consequently present the same general appearance 
as the parent. Here and there, however, through some 
subtle occult influence, cases present themselves where the 
offspring is found to display strongly marked characteristics 
of which not a trace existed in either parent or, so far as can 
be ascertained, in any of its progenitors. These sudden 
departures from the normal type (or sports, as they are 
horticulturally termed) seem frequently to result from some 
accumulated influence induced by the artificial conditions 
attendant in cultivation. This is shown by the fact that 
many flowers under such treatment are liable after a certain 
time to vary suddenly either in themselves or their progeny, 
a fact to which we owe the immense number of strongly 
marked forms of floral beauty now existent. 
In Ferns, however, under purely natural conditions—or, 
at any rate, under conditions as natural as we can obtain in 
a civilised country—there have been discovered an immense 
number of forms departing so widely from the normal types 
among which they were found, and which are so isolated in 
their occurrence and so entirely unaccompanied by any trace 
of intermediate aberration that we are forced to the con¬ 
clusion that they are the direct offspring of spores from per¬ 
fectly normal plants, notwithstanding which, they, in most 
No. 312.— Vol. XII., Third Series. 
cases, truly transmit their peculiarities generation after gene¬ 
ration to their offspring. 
What an extraordinarily subtle influence must that be 
which in either plant or animal can so affect and transform 
the microscopic germ that the resulting offspring shall not 
only differ materially from the parent form, but possibly an 
altogether different type of structure, at once symmetrical 
and beautiful, shall originate, and be able to transmit hence¬ 
forth its peculiarities to its offspring. Here, indeed, have 
we special creations, forming striking exceptions to the general 
rule of gradual evolution. 
To return to my special theme—Ferns. Take for 
instance the Victoria Lady Fern, and grant the assumption, 
which cannot be avoided, that it originated from a normal 
plant. This normal plant we found to consist of fronds 
formed of a central stipe tapering to a point, and provided 
with side branches or pinnae on the same plan and set on at 
an angle of about 30° ; these being again divided on the same 
principle, the whole forming a feathery frond of lanceolate 
outline. On the back of every frond there are millions and 
millions of microscopic spores, which, during the indefinitely 
long life of the plant, are shed around and blown about in 
countless myriads year after year, not only from this plant 
but from thousands like it in the vicinity. Suddenly one, 
and apparently only one, of these spores yields a plant in 
which all the divisions, pinme, pinnules, and pinulets are not 
only duplicated but much narrowed and set at about right 
angles to each other. The outline of the frond is also 
greatly narrowed, and finally the tips of the pinnae and the 
frond itself are many times divided, so as to form heavy 
tassels. Finally, it is abundantly sporiferous, and every 
spore is capable of reproducing its structural peculiarities; 
though, strange to say, the offspring are generally if not 
always easily distinguishable from the parents by a certain 
coarseness, the fine cutting of the ultimate division being, 
as it were, blurred and less sharply defined. On the other 
hand, I have raised hundreds of this form, and never saw a 
case of reversion to the normal form. This case of variation 
is an extreme type, involving as it does not merely a cresting 
but also an essential variation in plan of structure, a combi¬ 
nation of peculiarities which has so far not been discovered 
in connection with any other family of Ferns, though some 
few varieties are characterised occasionally by cruciate 
pinnae. This Fern was found growing wild by the roadside 
in Scotland, and though the station was assiduously searched 
then and later no second example or intermediate form was 
or has since been discovered there or elsewhere. Another 
extreme form was A. F.-f. acrocladon, found also by the 
roadside on a Yorkshire moor. Here the rachis and rachides 
possess such a tendency to division that the normal feathery 
nature of the frond is utterly lost, and the plant resembles a 
number of mossy balls crowning the much-divided stipes. 
Here, again, no intermediate form was found in the vicinity, 
and the necessary conclusion is that it originated at one 
jump, as it were, from the normal form. This case, how¬ 
ever, is not so striking as that of A. F.-f. Victoriie, since the 
ramification of the rachis is a comparatively common form 
of variation, and is only carried in this instance to an extreme 
extent. This again yields, I believe, fairly true progeny, in 
one of which the division is carried to such an extent that 
the whole plant resembles a ball of velvet. 
This power of cresting, in which the normally acute points 
of the rachis and rachides, of frond, pinnie, and even of the 
pinnules become dilated and divided, seems common to all or 
nearly all of the British Ferns, only one or two species having 
failed so far to afford instances; and since, as I have said, 
the more marked departures have been found wild, it becomes 
a question whether exotic Ferns all over the world will not 
yield instances of the same phenomenon when sought for by 
an eye accustomed to the quest; for it is a peculiar fact that 
until the sight becomes habituated to the search for special 
features the eye unconsciously is liable to overlook and pass 
No. 1968.— Vol. LXXIV., Old Series 
