There are plenty of good-looking spores on Lustrea remota, yet they will not germinate. For the last ten years several pans of spores from this form have been sown yearly without a single plant having been raised.
It has been also a question with the author as to whether some of the forms of species that only bear sterile fronds may not also be hybrid species. All the varieties of the species will reproduce the abnormal forms as prolificly as the normal ones, whilst a so-called hybrid species will not reproduce.
There are not only abnormal varieties of ferns, but the normal forms of different localities differ so that when the common forms of certain localities are gathered together they display in a marked degree the departure from one form.
In nature the progress of change in form is very slow, although in the forms of some plants a more rapid development in some localities can be observed: thus, nearly all the Harts tongue ferns at Westward Ho; on the Castle Rocks, Scarborough; and at Dawlish, are once or twice branched or crested. These changes. however, become much more rapid when under the most favourable circumstances, such as obtaining a pedigree and continuing it.
With regard to the origin of species, it is learnt from the doctrine of evolution, that all are the descendants of a comparatively few originally created simpler forms; this doctrine teaches, (I now quote Sir Joseph Hooker's admirable Botany):—1st. That the descendant of every plant departs more me or less in character from its parents. 2nd. That of these variations, some are better fitted than others. and even sometimes than their parent was, to survive in the area the plant inhabits. 3rd. That the conditions of the area are, like the individuals, variable. 4th. That the number of details previous to maturity amongst the descendants is enormously greater than that of survivors, and that those deaths are due to the conditions of the area not having suited them. 5th. That the descendants best fitted to thrive under the conditions of the area will be the survivors. 6th. That these variation will hence ultimately, in certain places, supplant the parent form; and 7th. That the differences between a species and a variety being one of degree only, the variations (illegible text) through successive generations will become specific, and these again by a like process generic, and so on.
No investigations demonstrate in a more striking manner the truth of this Darwinian theory than such as this paper briefly demonstrates. There is undoubtedly a mathematical law in the changes of form, and this fact proves that Dr. Darwin's discoveries have vastly advanced our knowledge of the laws of nature.
On an Improved Aneroid Barometer.
By W. J. Harrison, Esq., F.G.S.
An instrument which shall accurately indicate differences in level or height above the sea is much needed by practical men of science. The geologist requires it to ascertain the varying heights of his beds of rock, thy zoologist and the botanist to know the limits of the zones of animal and vegetable life, and it is of not less service to the meteorologist, the surveyor, the engineer, and the traveller.
