72 SUPPLEMENT 



In the amphitritse, we may very well trace along the bran- 

 chial cirrus a nervous thread, which accompanies the vas- 

 cular system. 



One of the singularities presented by the chetopoda is, that 

 their recrementitious fluid, or the blood, is almost constantly 

 red, the aphrodites excepted. Of the cause of this we are 

 entirely ignorant. 



Their phosphoric property is altogether remarkable, at 

 least in the smaller species. From this Linnaeus long since 

 denominated one of their species nereis noctiluca. M. 

 Viviani has likewise noticed one of them among the animals 

 to which he attributed the phosphorescence of the waters of 

 the sea of Genoa. 



The chetopoda have in general been too little observed in 

 the living state, and especially for a sufficient time, to en- 

 able us to know any thing with certainty respecting their 

 physiology, or their natural history. 



We only know from the experiments of Muller, that the 

 nereides and the naides are capable of reproducing the parts 

 of their body which have been amputated. 



The chetopoda are almost all aquatic, the earth-worms 

 excepted, and even those, to a certain point, may be regarded 

 as such, so much need have they of humidity, and so much 

 do they fear, and are injured by drought. A great part of 

 these animals live in the waters of the sea. It may be even 

 remarked, that there are few marine beings that perish so soon 

 when they are put into fresh water. The majority of the 

 naides live in fresh water. It would appear, too, that though 

 the nereides generically belong to the sea, that some true 

 species may be found in the lakes of North America. 



Some of these animals are to be found in all quarters of the 

 world, and, except the Amphinoma;, which have not yet been 

 met with except in the seas of warm latitudes, and particu- 



