CHAPTER IV.

THE PLANTS.

As already stated, the green weeds are most suitable, the red next so, but of the brown and olive sorts there are very few that can be kept in a state of health for any length of time. There are only two plants suitable for the commencement of the experiment, and these are _Ulva latissima_, the common sea lettuce, and _Enteromorpha compressa_, a delicate grass-like algæ, of a very cheerful green. Of these Mr. Lloyd and Mr. Hall have always plenty on hand, ready cleaned and prepared for immediate submersion. Artificial water soon acquires the properties of natural sea water under the influence of these plants, which grow rapidly, and disseminate their spores throughout the tank, at the same time giving abundance of oxygen for the support of animal life.

When a few weeks have elapsed _Chondrus crispus_, better known as "Carrageen moss," may be added, it is a free grower found in plenty on the ledges at extreme low-water mark. The green weeds _Codium tomentosum_, _Cladophora arcta_, and _rupestris_, and _Bryopsis plumosa_ may be considered safe stock when the water has been in use a month or two, but the growth of the more delicate of the Rhodosperms must not be attempted in artificial water for at least three or four months.

The best weeds of the latter class are _Phyllophora rubens_, _Corallina officinalis_, and _Iridæa edulis_. In collecting, no doubt the Dulse, _Delesseria alata_, and _sanguinea_, with, perhaps, some of the _Polysiphoniæ_ will be considered valuable prizes, but they will not succeed in any but experienced hands, for whom this work is not written.

_Dasya_, _Chylocladia_, _Nitophyllum_, _Griffithsia_, _Rhodymenia_, and _Ptilota_ will all contribute specimens as time goes on, and opportunity affords for obtaining them. But not one of these lovely weeds of the red class are fit for ordinary aquarian tactics, they are the "florists' flowers" of the aquarian world, and refuse to be domesticated by any but adepts. The exquisitely delicate _Griffithsia setacea_ is perhaps the only one of the above that may be safely used in a well-seasoned tank of artificial water; the other genera seem to be still more delicately constituted and to require their own native element in a state of great purity.

Once more I urge the beginner to be content with Ulva and Enteromorpha at starting, with half-a-dozen plants of each of these, a large and pleasing variety of animal life may be preserved, and in the case of disaster of any kind, these are the most readily restored to health by a little timely and judicious management.

All coarse and dark coloured weeds, however tempting at first sight, are to be avoided. The sprawling tangles that one steps over in traversing the boulders and the slimy masses of sea-weed, everywhere cast upon the coast, are quite unfit, however fine the specimens, or strong the desire to possess them. Neither must much value be attached to any weed cast up by the surge. The only trustworthy specimens are those chipped from the rock _in situ_ and brought away without being detached from their natural basis.