RULES FOR PRESERVING, ETC. 



XXVll 



Delesseria (now Worms Jcioldia) sanguinea (Fig. 169), preserves its colour better when 

 the wet blotting-papers are changed very quickly, 



Mesofjloia vei^micularis (Fig. 55), and virescens (Fig. 57), Gloisiplionia capillaris 

 (Fig. 219), Forphyra laciniata, and any very gelatinous plants, should never have their 

 muslin removed under any of the changes of the blotting-papers: not, in sliort, till they 

 are completely dry. 



Several of the thin flat expansions, as the Rliodymenias, Nitopliyllums, Iridma, HJio- 

 dopJiyllis, Callopliyllis, Kallymenias, Halymenia, TJlva, &c., contract so much in drying, 

 that ample allowance should be made for it, by laying them very easily on the paper — 

 never stretching them to anything like their full ivet length. Otherwise, when dried, 

 they will crack in all directions. Rough-dried specimens require the same treatment as 

 fresh ones, except that they will need soaking to induce them to expand. The coarse 

 olive plants should never be left soaking with finer ones, as they give out a slimy juice. 



Codium hursa (Fig. 284) is a specialty, and must be specially treated. It is a thick 

 lump, and must be pressed alone and very gradually, or the frond will crack and burst; 

 the pressure being increased day by day as the lump subsides. It may be made quite 

 flat at last, but time and patience are necessary. If two or three growing in a close 

 group are pressed together, put little bits of muslin between them, and do not remove 

 these till the process of pressing is completed. Some people prefer preserving it in a 

 bottle with spirits of wine and water (one part spirit, two water). This plan has the 

 advantage of not destroying its shape, but the bottle is inconvenient in the herbarium. 



Leatliesia tuberiformis (Fig. 54), and the Rivularias (Plate LXXV.), require gradual 

 pressing also. 



Certain incrusting plants, as Ralfsia verrucosa (Fig. 60), Cruoria pellita (Fig. 227), 

 (now Petrocelis cruentd), Ilildenbrantia rubra (Fig. 161), &c., cannot be displayed on 

 paper. Morsels of them may be kept in little paper cases fastened in the herbarium, 

 but dissected portions of each should be mounted in microscopic slides for observation 

 of the structure. 



The lumpy Melohesias (Figs. 156 — 159) can only be kept in boxes. 



