Directions for preserving Sea Plants. 157 



being pale, and in others a rich reddish-purple ; sometimes a bright 

 orange, which latter, I believe, is the effect of incipient decay. I 

 often observed it at Cairnlough, when floating in still water, to have 

 an appearance as if it were bordered with white, and on closer in- 

 spection I found that this proceeded from the margin having attached 

 to it in its whole extent minute air bubbles, which in certain lights 

 looked exactly like a regular row of seed-pearl. On disturbing the 

 plant, these bubbles were not very easily dislodged. They appeared 

 equally in shade as in sunshine. 



Polysiphonia violacea. — Abundant at Cairnlough Bay, in May, and 

 in fruit in June. When put in fresh water, it almost immediately 

 gives out a cloud of colouring matter, of the tint of Roman ochre, 

 and becomes much darker in colour than before. When it has lain 

 for a night in a wet state on the edge of a dish, I have found it on 

 the following day to be almost black. When rolled in a large bunch 

 on the shore by the action of the waves, its long fasciculated 

 branches become so ravelled, that it is alm-ost impossible to get them 

 disengaged from each other, and from this cause I lost some fine 

 specimens, as I found*the task of unravelling them too trying for 

 any ordinary degree of human patience. It adheres firmly to paper. 



Dasya coccinea. — Common. When quite fresh, it is of a garnet-red 

 colour, and, like most others of that tint, it becomes of a beautiful 

 rose pink, when macerated in fresh water. 



Ceramium ruhrum. — I found a number of specimens of this very 

 common plant, with distinct capsules imbedded in the substance of 

 the filaments. The central parts of these were so opaque, that I 

 could not with the microscope distinguish separate seeds, but each 

 globular mass was surrounded by a hyaline ring, and in some speci- 

 mens, where, from decay, the filament had become white, the glo- 

 bules retained the same intensity of colour as in other parts ; shew- 

 ing that their vital properties had protected them from the decaying 

 process to which the part containing them had yielded. 



I have an interesting specimen of Delesseria sinuosa, which is 

 bleached almost as white as the paper on which it lies ; but the cili- 

 ary processes upon its margin, containing the seeds, are of the usual 

 colour and form, a beautiful contrast with the rest. It seems to me 

 indeed not improbable that cases might occur where attention to cir- 

 cumstances of this kind might throw some light on the reproductive 

 parts of some of these tribes. 



Griffithsia setacea. — Common on the Antrim coast. It was chief- 

 ly in reference to this species that I threw out a caution with regard 



