XXVm INTRODUCTION. 



already more than once published, may prove interesting to 

 those who have not seen it, and perhaps tempt botanists 

 whose residence near the sea gives them an opportunity, 

 to repeat the trial. " Having procured a number of wide- 

 mouthed jars, together with a siphon to draw off the water 

 without shaking or disturbing it, on Sept. 7, 1796, I placed 

 my plants {F. serratus, cannliculatm and tuherculatiis) 

 carefully in the jar, with their bases downwards, as in their 

 natural state ; on the following morning I decanted off the 

 sea water, and, letting it subside in the basin, 1 found a 

 few particles at the bottom, which on being viewed with 

 the microscope appeared to be little fragments detached 

 from the surface by friction in carriage. 1 then poured a 

 fresh quantity of sea water on the plants, and placed them 

 in a window facing south : on the following morning the 

 jar containing the plants of F. canaliculatus discharged 

 into the basin a few yellowish grains, which, on examining 

 them, I found to be the actual seeds of the plant ; they were 

 rather oval than pear-shaped, but the most curious circum- 

 stance attending the observation was, that each individual 

 seed was not in contact with the water, but enveloped with 

 a bright mucilaginous substance. It was easy to guess the 

 wise economy of nature in this disposition, which, as hinted 

 above, serves a double purpose ; each equally necessary 

 towards continuing the species. On the following morning 

 a greater quantity of seeds were discharged by this plant, 

 and at this time a few seeds were procured from F. serratus ; 

 but this latter plant discharged such a quantity of mucous 

 fluid that the sea water in which the plant was immersed 

 was of the consistence of syrup, and consequently, the seeds 

 being kept suspended, it was difficult to separate them. 

 The seeds of F. canaUculatus, however, were numerous, 

 and visible to the naked eye, and after letting the water 

 rest for a {aw minutes it was no difficult matter, by gently 



