GREEN LAYER. 



67 



of animals may be captured with hardly any 

 trouble. They will live perfectly well in the 

 vessel if it is kept in a light spot with a free 

 circulation of air. 



The Common Green Laver (JJlva latisstma), 

 plate K, fig. 6, sometimes called the Sea Lettuce, 

 is found most abundantly on the same spots as 

 the preceding plant. Of all the sea-weeds for an 

 aquarium, the Green Laver is perhaps the very 

 best. It is very pretty, from its delicate green 

 colour, and the various folds and puckers into 

 which it throws itself. Its power of expiring 

 oxygen seems to be almost unlimited. I have in 

 my aquarium a large plant of this species, which 

 generally lives very contentedly in the place 

 where it had been deposited. But, a few days 

 ago, the sun shone brightly enough to pierce 

 through the veil of smoke with which the metro- 

 polis is generally hidden from his presence, and 

 consequently there was a greater abundance of 

 light than usual. On looking at the aquarium, 

 I found that the ulva had risen in the water, and 

 was hanging in most elegant festoons from the 

 surface, forming emerald caves and grottos such 

 as the sea-nymphs would love. Even at a little 

 distance it was a pretty sight, but a closer in- 

 spection revealed still more beauties ; for being 



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