ON SEA- WEEDS. 149 



candle be placed at the edge of the tank, it will soon 

 be seen that the diet is not altogether imaginary. 

 Thousands of minute but lively shrimps, and other 

 objects, may be seen, even with the limited vision of 

 the naked eye, swimming about in all directions, 

 making for the light. If these are examined with a 

 hand-lens, the marvel of the appearance will "be not a 

 little increased. The Sea-grass, as its common but 

 expressive name would lead us to suppose, grows in 

 thin wiry fronds, although occasionally I have seen 

 it half an inch broad. A novice is apt to be led 

 away with the idea that it is a juvenile specimen of 

 the broad green Ulva. 



There is another plant, Zostera marina, that in like 

 manner bears the generic name of Sea-grass. It differs 

 from that which we have been describing in this 

 important respect, that it grows with a root " on 

 sandy shallows and banks in the sea. It has very 

 long grass-green leaves, and hence its botanic name is 

 derived from the Greek word riband. The French 

 term it La Zostere, the Germans Sea-tang, and our 

 own coast people commonly call it Sea-grass." It is 

 frequently torn up by the force of the waves, and 

 thrown upon the shore, where it soon becomes of a 

 brown or blackish hue. Most of my readers will 

 know it by its commercial name of Ulva, or Alva 

 marina, it being used extensively in many places for 

 the purpose of filling beds and mattresses in lieu of 

 horse-hair and other expensive material. 



I was much pleased on meeting with a passage in 



