16 SOME SPECIES TO EE KEPT SEPARATE. 



mouthed, holding about two or three ounces each, are 

 best suited to bring home these species.* 



I must now caution young beginners to keep apart 

 from other plants all the different varieties of the genus 

 Desmarestia, for they possess the peculiar property of 

 changing the colour of, and very soon decomposing, all 

 other plants, especially those of the finer species, with 

 which they may come in contact. 



Notwithstanding what has been alleged to the con- 

 trary, most of the Desmarestia?, if kept out of sea-water, 

 even for a very inconsiderable time, soon become flac- 

 cid, and rapidly advance towards decay. Specimens of 

 Desmarestia viridis, taken in the spring, which are ex- 

 ceedingly beautiful, if properly laid out, are very difficult 

 to preserve, and can scarcely be brought from any great 

 distance without being decomposed, or fast approaching 

 to that state. It is therefore necessary to remember 

 that these plants should always be brought home in ves- 

 sels filled with sea-water, and that only a few specimens 



* A precaution often absolutely necessary, for many of 

 the delicate red Algae rapidly decompose, if exposed, even 

 for a short time, to the air, or if allowed to become massed 

 together in the same bottle, as crowding" encourages de- 

 composition ; and when this has once begun, it spreads 

 with fearful rapidity As many of these Algae will not 

 keep, even in large vessels of sea-water, from one day to 

 another, the sooner they are arranged for drying, the better. 



