To collect seaweeds one must search for them on rocks, in tide-pools, in the sea-wrack upon the beach, on piles of wharves, on eel-grass, and on the surface of incoming waves. It is well to follow the receding tide and take advantage of its lowest ebb (especially of that of the spring-tides, as mentioned above) to search the extreme limit of the beach in the short time it is exposed. Many of the red seaweeds are found there.
The equipment for collecting consists of a basket, two small tin pails, one small enough to be carried within the other, a staff with an iron edge at one end and a small net at the other, and a pocket-lens. Rockweeds (/Fucus/) or other coarse gelatinous seaweeds should be put into the basket. The pails, half filled with sea-water, will receive the other specimens, fine and delicate algæ being put into the smaller pail. It is well to have a second small receptacle for /Callithamnion/ and /Griffithsia/, if one can be further burdened. /Desmarestia/ should be kept apart, if possible, since it discolors and decomposes other algæ; it should also have the earliest attention when the time comes for mounting, and salt water should be used for floating it upon the mount, otherwise the beauty of the specimen will be impaired.
Besides its use as a support, the staff is needed to dislodge specimens from the rocks, and the net to secure those that are floating just out of reach. When possible, it is desirable to secure the whole plant, including the holdfast, and to gather several plants of the same species, since they vary with age and other conditions, and it is also well to have duplicates for exchange. It is particularly desirable to obtain plants which are in fruit. Each specimen as it is taken should be rinsed in the sea-water to free it from sand.
Collections should be mounted as soon as convenient, and [pg016] especial care in this respect should be taken with red algæ, as they decompose quickly. The requisites for mounting are blotters, pieces of muslin, two or more smooth boards, weights, a basin, and several shallow dishes containing water. Fresh water has a strong action on the color and substance of seaweeds, and specimens should not be left in it for any length of time.