312 THE MARINE BOTANIST. 



mosaic work; the spores are formed one or four 

 in each cell, from the endochrome or colouring 

 matter contained therein. The colour of the "green 

 sea-shore" is chiefly owing to the abundance of 

 such common species as Ulva latissima and Entero- 

 morpha compressa ; they, as well as the Porphyrse, 

 are equally frequent on the shores of the Arctic 

 and Antarctic oceans. The latter genus dififers in 

 its purple colour from others of this series, but 

 resembles the grass-green sea-weeds in respect of 

 fructification and structure. Their fronds are 

 gathered on our coasts, and boiled down into 

 "laver/* which forms a wholesome and agreeable 

 vegetable. In its prepared state it may be pre- 

 served for an indefinite time in closed tin vessels ; 

 and in the absence of other vegetables, Dr. Harvey 

 believes it would become a valuable article of diet 

 to the crews of our whaling vessels cruising in high 

 latitudes, where every marine rock at half-tide level 

 abundantly produces it. Bangia, a genus which 

 contains two or three marine species, with fila- 

 mentous fronds, of a dull purple colour, consisting 



