In the earlier stages of development in this genus, the clusters of fructification appear to be furnished with a somewhat scaly involucre, which apparently passes away as the frond approaches maturity, leaving a kind of fringed or torn involucre beneath it, which is, I believe, the principal difference between the present genus and the preceding, with which it was, some years ago, associated. There is besides a considerable difference in general habit.

1. W. Ilvensis

This may truly be said to be a rare British Fern; and to all appearance it is very likely to remain so, as I am given to understand that in some of the few known habitats it is now all but eradicated. Yet the plant is by no means so difficult to cultivate as some of the other small species of British Ferns. If intended for the fernery, it must be strong before it is turned out of its pot, when it will require peat, loam, and sand in equal quantities; in addition to which it should have a well-sheltered and shady corner, where slugs are not much in the habit of frequenting, as they are one of the greatest enemies to the fronds in their young state.

I can well remember, some thirty years ago, when I had a plant forwarded to me from Scotland by my old and worthy friend Mr. S. Murray, of the Royal Botanic Gardens, Glasgow, but which was, I have no doubt, the following, Woodsia hyperborea. I cultivated this plant for many years in a sheltered corner or nook, among some large flints, overhung by some of the larger kinds of British Ferns, which proved both excellent shade and shelter for it. Here the plant in question luxuriated for many years without being disturbed in the way of propagation; neither had I then quite so much need for that kind of practice as has fallen to my lot since, - at least so far as the present plant and the W. hyperborea are concerned. But this 1 hold to be applicable to many of the other native Ferns, as well as the two Woodsias; as, in fact, daily experience teaches us that many of our rarer kinds of British Ferns are totally destroyed by over-anxiety to increase their numbers. Even W. Ilvensis will send forth plants or offsets from its roots, which, if allowed to remain, will soon form a tuft or strong plant; but if repeatedly taken away, the operation will doubtless ultimately destroy the original plant.

2. W. Hyperborea

This requires similar treatment to the last species, from which, however, it can scarcely be considered specifically distinct; for if we take into consideration the less degree of hairiness and more obtuse form of the pinnse - and these characters not always very constant - we shall be a little disposed to hesitate before we pronounce them distinct species; at all events, I confess that I have often been at a loss to detect them in certain stages of their growth, more especially so far as hairs or scales are concerned. May not the different forms be traced to soil and situation, as I have at times supposed my English plants to differ from my Scotch ones?

Nursery, Foots-Cray. Robert Sim.