In some articles published in 'Science-Gossip' a few years ago, I gave some directions for collecting and preserving Marine Algæ, or seaweeds, and although, I think, it will be difficult to simplify those directions, or even to add much that would be really serviceable to young beginners in this delightful pursuit, it is my intention, in going over the ground once more, to be as explicit as I possibly can; and here, on the threshold of the subject, I have a few words to say to one or two occasional contributors to that journal, who, in calling attention to the beauty of marine vegetation, and urging young persons to collect and preserve Algæ, have advised them to ignore books on the subject, and go to the shore, use their own eyes, and collect for themselves, &c. I am sorry very greatly to differ from such advice. Collecting in this way may be amusing enough to those who care not for science, but when it leads to parcels of seaweeds, picked up at random, being sent to botanists with a request that the names of such plants should be sent to the writer, it is the reverse of pleasure to the scientific botanist, for it gives him infinite trouble, and enables him to convey but very imperfect information to his applicant. The editor of that journal has often been thus appealed to, and packages of decayed rubbish have frequently been sent to me for examination, containing species or rather fragments of plants, which, for the most part, were utterly worthless and defied identification. Almost all collectors commence by mounting plants which a little experience proves to be really what the old poet termed "_alga projecta vilior_"; but as seaweed-gathering, like everything else, requires practice, beginners must not be disappointed because they do not find rarities or fine specimens whenever and wherever they may seek for them.