VEGETATION OE SEA-WEEDS. 23 



Tth of September^ 1796, he placed plants of Fuciis canali- 

 culatu% in the jar with their bases downwards. On the 

 following morning he decanted the water into a basin. He 

 then poured a fresh quantity of sea-water on the plants, 

 and placed the jar in a window facing the south. On the 

 following morning the plants discharged a few yellowish 

 grains, which proved to be the actual seed of the plant ; — 

 these seeds, however, were not in contact with the water, 

 but each enveloped with a bright mucilaginous substance, 

 which, from being heavier than the water, made it sink, and 

 caused it to adhere to the rock. Watching these seeds, he 

 had the pleasure of seeing one of them exploding so as to 

 agitate the water, from which he learned that some sea- 

 weeds, when ripe, scatter their sporules by the bursting of 

 the capsules without waiting for the decay of the frond. 



He next got pebbles from the sea-beach, and having 

 drained off the greater part of the water, he poured the 

 remainder on the pebbles and left them to dry for some 

 time that the seeds might adhere to them. He then fastened 

 strings to the pebbles, and alternately sank them in the 

 jar, and drew them out and left them exposed to sun and 

 rain, in imitation of what would have been experienced by 

 them by ebb and flow at mid-tide mark, had they been in 



