Mr Murray on the Paragrelc or Protector from Hall. 107 



e. Thorns, brambles, or furze, surrounding the pole, to secure it 

 ^ from injury. 



Note That part of the wood which enters the earth should be 



charred, to preserve it from moisture ; while the remainder of 

 the pole may be varnished, the better to secure its non-con- 

 ducting character. The vai'nish of Lampadius, composed of 

 a mixture of linseed oil, sulphate of copper, and lead, will be 

 found remarkably good for this purpose. 



Observations on the Structure and Nature of' Flustra. *. By 

 R. E. Grant, M.D., F.R. S. E., F.L.S., W.M.S., former- 

 ly Lecturer on Comparative Anatomy in Edinburgh. Com- 

 municated by the Author. 



JL HE regular forms of the cells of Flustra?, their close and 

 exact arrangement, and the elegant foliage which they form by 

 their union, early attracted the notice of naturalists; and the 

 great flexibility, transparency, and ramified appearance of these 

 substances, caused them to be universally regarded as marine 

 plants, till Jussieu, by his discovery of the polypi of the Flustra 

 foliacea {Mem. de TAcad. 1742), assigned them a place in the 

 animal kingdom. The interesting observations of Jussieu on 

 that species, of La?fling on the polypi and formation of the new 

 cells of the F. pilosa, Ellis on the structure and forms of the 

 cells of many British species, Basterus on the spontaneous mo- 

 tions of the small bodies which escape from the apertures of the 

 cells, Pallas on the mode of formation of the cells and on the 

 nature of the bullae at their summits, and of Spallanzani on the 

 structure and appearance of the polypi, have shewn that these 

 animals possess a highly complicated organization, and have 

 some of the characters of compound animals or zoophytes. Ellis 

 has shewn that the forms of the cells vary remarkably in differ- 

 ent species, presenting an obvious and useful character for their 

 discrimination ; and nearly forty species of these animals, recent 

 and fossil, are desc^'ibed by authors. No writer, however, has 

 yet examined the minute structure, the mode of growth, and the 



* Read before the Wernerian Natural Historj' Society of Edinburgh on 24th 

 March 1827. 



