CHAP. I.] THE EQUIPMENT OF THE SHIP. 95 
would be worth while attempting to preserve specimens for future mi- 
croscopic examination by means of osmic acid. * 
25. Alge.—Marine algze may be found between tide-marks attached 
to rocks and stones, or rooting in sand, etc.: those in deeper water are 
got by dredging, and many are cast up after storms; small kinds grow 
on the larger; and some, being like fleshy crusts on stones, shells, etc., 
must be pared off by means of a knife. 
The more delicate kinds, after gentle washing, may be floated in a 
vessel of fresh water, upon thick and smooth writing or drawing paper ; 
then gently lift out paper and plant together, allow some time to drip ; 
then place on the sea-weed clean linen or cotton cloth, and on it a sheet 
of absorbent paper, and submit to moderate pressure—many adhere to 
paper, but not to cloth; then change the cloth and absorbent paper till 
the specimens are dry. Large coarser kinds may be dried in the same 
way as land-plants; or are to be spread out in the shade, taking care to 
prevent contact of rain or fresh water of any kind; when sufficiently 
dry, tie them loosely in any kind of wrapping-paper; those preserved 
in this rough way may be expanded and floated out in water at any 
time afterward. A few specimens of each of the more delicate alge 
ought to be dried on mica or glass. A note of date and locality ought 
to be attached to every species. 
Delicate slimy algze are best prepared by floating out on smooth-sur- 
faced paper (known as ‘“‘sketching-paper”), then allowed to drip and 
dry by simple exposure to currents of air, without pressure. 
26. Very little information exists regarding the range of depth of 
marine plants. It will be very desirable that observations should be 
made upon this subject, as opportunity from time to time-presents itself. 
Professor Dickie remarks, and the caution should be borne in mind: 
‘When the dredge ceases to scrape the bottom, it becomes, in its prog- 
ress to the surface, much the same as a towing-net, capturing bodies 
which are being carried along by currents, and therefore great caution 
is necessary in reference to any marine plants found in it. Sea-weeds 
are among the most common of all bodies carried by currents near the 
surface or at various depths below, and from their nature are very likely 
to be entangled and brought up.” 
27. Carefully note and preserve algee brought up in dredge in moder- 
ate depths, under 100 fathoms, or deeper. Preserve specimens attached 
to shells, corals, ete., which would indicate their being actually cn situ, 
and not caught by dredge as it comes up. 
