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ADDITIONS TO THE IRISH MOSS FLORA. 237
the most nortlicra latitudes of our islands, where the normal erect
state seems to be wanting ; for here the plant seems to be unable
to grow except in tolerably deep water, and consequently always
assumes its floating state.
llyhridity.—There is no doubt in my own mind that the different
species occasionally cross, though perhaps not so frequently as in
some other genera. The best instances have come before me in
Shetland, where S. ajfinc grows intermixed with the floating state
of 5. simplex. The resulting hybrid differs from both of the parents
in being totally sterile, while in its more erect habit (thus
approaching the normal form of S. simplex, which does not occur in
Shetland), the greater vegetative activity, common in sterile hybrids,
is shown. The other characters are intermediate. I have received
from Dr. Neuman Swedish examples of this hybrid, as well as of
S. rainosum X simplex. In Britain I have seen examples which are
probably hybrids S. ramosum x nei/lectuia and S. neylectum X simplex,
but concerning these further observation is necessary.
The Stiijma.—What has hitherto been called the " style" is in
reality a true beak of the fruit. The stigma is sessile, or it may be
regarded as a style which is stigmatic on one surface throughout
its whole length. It is obliquely decurrent on the beak for a very
short distance. In dried specimens the difference is not perceptible,
but in fresh fruits the beak is seen to be of the same colour and
herbaceous texture as the rest of the fruit, and its junction with the
hyaline stigma, obliquely sessile on its apex, is easily seen.
Fertilisation.—Dr. Focke has well remarked* that the Sparnania
are eminently proterogynous. So far as I have observed, they are
chiefly wind- fertilised ; while in the floating species the pollen is
doubtless sometimes carried to other plants on the surface of the
water. Neither the erect nor the floating forms appear to be visited
by insects except by rare accident.
The subject of hybridity in this genus seems to afford considerable
opportunity for further research, but continued out-door
observations are necessary ; and a ground-work of knowledge,
founded on the study of the plants as they grow, is an essential
preliminary to the comprehension of the often illusory characters
presented by dried specimens whetber of the hybrids or the species
themselves. Unfortunately tlic preliminary is too often neglected,
not alone in this genus, and the resulting consequences cannot fail
often to appear grotesque, at least to those who know something of
the plants themselves and not their reputed measurements merely.
ADDITIONS TO THE IRISH MOSS FLORA.
By David McArdle.
In the April number of the ' Revue Bryologiquc,' there is an
interesting note on ll>/p)ium rii-'iiuilr Hook, by M. J. CardoL, an
eminent French botanist, who detected it amongst some mossea
• Ahhandl. Niitnrwisa. Ver. z. Brpmen, v. p. 40!».