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98 NOTES ON ENGLISH RUBI.
of a few dried branches can lead to a real acquaintance witli a
difficult bramble. It would be more instructive to examine the
living plant, but nobody can visit all localities where doubtful
species are growing.
It would be tedious to enumerate all the various difficulties
"which we cannot escape in these researches. The question arises
are we obliged to waste our time in studymg the foolish writings of
every ignorant and mischievous manufacturer of names ? A neglect
of such productions has nothing to do with the esteem we pay to
the work of our true predecessors in science.
Several botanists have thought that knowledge would profit
more from a diminution of the numerous species than fi'om an
increase. Therefore they combined a great number of different
forms, producing in this manner an aggregate species. The easiest
way to escape all difficulties would be to establish a liiibus i>ohjworphus,
as Spanner did. In following his example we either
obstruct scientific research, or, if we admit subspecies and varieties,
we change the terms only. At present we are accustomed to say
Tailim suhercctns, R. plicutus, &c., but it is a matter of mere
convenience if we should prefer to alter this nomenclature into
E. fntticnsits subsp. suherectns and snbsp. plicatiis. Science would
neither be improved nor damaged by this arrangement. In other
groups of our brambles the question is much more intricate.
Certainly the limits of the separate forms are often very difficult
to trace ; but between the aggregate species, comprehending all
connecting links, exist no limits at all.
My own opinion is that in such genera as Rubus, Rosa, Tlierdcinw
and many others, hybridization once has mixed the old species,
with the effect of producing, in the course of many hundred years,
numerous new species of a lower order. At present we see exactly
the same occur in the Rhododendrons, Fuchsias, Begonias, Abutilous,
and many other favourite plants of our gardens. In all the
second-rank species, originated in tlie woods or in cultivation, the
jDollen contains a considerable number of imperfect grains. There
are only three English blackberries which have quite regular
pollen-grains, viz., R. cceuus, R. rusticainis, and R. firatiis.
These views do not necessarily lead to the conclusion that at
present there must take place abundant intercrossing between all
our existing brambles. R. cashis, R. restitus {leiicostachijs), and R.
nisticaniis (on the Continent R. tomentosxis and R. rudis too) are very
much inclined to produce hybrids as well inter se as with many
other species. Everywhere we observe associated with them a good
many perplexing intermediate forms and connecting links resisting
all attempts at classification. We must not fancy that hybrids are
always rare. On the Continent the R. casiiis x Lhciis, a hybrid
which I have produced artificially, is in many districts a common
plant, although it very seldom bears a single fruit, and is usually
altogether sterile. Frequent hybridization, however, is not a general
rule among our brambles. On the contrary, hybrid brambles,
which are not procreated by one of the few species named above,
are of rather rare occurrence.