NARRATIVE OF THE CRUISE. 31 



24. In the case of the Hyxogastres, sketches should he made on the spot of their general form, with details 

 of microscopic appearance. It would he worth while attempting to preserve specimens for future microscopic 

 examination hy means of osmic acid. 



25. Alga;. — Marine algae may he found between tide-marks attached to rocks and stones, or rooting 

 in sand, &c. ; those in deeper water are got hy dredging, and many are cast up after storms ; small kinds 

 grow on the larger, and some heing like fleshy crusts on stones, shells, &c, must he 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 afterwards. A few specimens of each of the more delicate alga? ought to be dried on mica or glass. 

 A note of date and locality ought to be attached to every species. 



Delicate slimy algaa are best prepared by floating out on smooth-surfaced 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 progress 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 algae brought up in dredge in moderate depth, under 100 fathoms or deeper. 

 Preserve specimens attached to shells, corals, &c, which would indicate their being actually in situ, and not 

 caught by dredge as it comes up. 



28. Examine mud brought up by dredge from different depths for living diatoms ; examine also for the 

 same purpose the stomachs of Salpm and other marine animals. 



29. Note alga? on ships, &c, with the submerged parts in a foul condition ; also preserve scrapings of 

 coloured crusts or slimy matter, green, brown, &c. 



30. Observe algae, floating, collect specimens, noting latitude and longitude, currents, &c. 



31. Examine loose floating objects, drift-wood, &c, for algae. If no prominent species presents itself, 

 preserve scrapings of any coloured crusts. Note as above. 



32. It might be useful to have a few moderate-sized pieces of wood, oak, &c, quite clean at first, 

 attached to some part of the vessel under water to be examined, say, monthly. The larger or shorter 

 prominent algse should be kept and noted, and crusts on such examined and preserved, with notes of the 

 vessel's course. 



33. Various instances have been mentioned by travellers of the coloration of the sea by minute algae, as 

 in the Straits of Malacca by Harvey ; any case of this kind would be worth especial attention. 



34. The calcareous algas (Melobesia, &c.) are comparatively little known, and are apt to be overlooked. 



35. Freshwater alga? should be collected as occasion presents. Professor Dickie states that they may be 

 either dried like the marine kinds, or preserved in a fluid composed of 3 parts alcohol, 2 parts water, 1 part 

 glycerine, well mixed. 



36. Cases are recorded of the presence of algae in hot springs. If such are met with, the temperature should 

 be noted and specimens preserved. 



