6o AQUATIC MICROSCOPY FOR BEGINNERS. 



Rl'CCIA FLUITANS (Fig. 16). 



Near the writer's home this little floating plant (pro- 

 nounced ricksid) is so abundant that it often covers 

 small pools with a layer two inches 

 deep. Elsewhere, on larger ponds, 

 it is notuncommon. It often comes 

 to the collecting-bottle tangled in 

 the leaves of Utricularia, Myrio- 

 phyllum, or Ceratophyllum, or it 

 floats on still waters in little island- 

 Fig. le.-Riccia fltoans. like patches. Its form is seen in 

 Fig. 16. 

 It has no leaves; indeed it is all leaf; the botanist 

 calls it a radiately expanding frond, with narrow di- 

 visions, whose ends are notched. The plant is green, 

 and may be an inch or more wide when sprea!d out, 

 and is often larger and more branched than shown in 

 the figure. It has no roots, but floats freely wherever 

 the currents or the winds send it. Shady places seem 

 to be its favorite haunts. 



As a microscopic object it is rather large and thick, 

 but it forms a good place to examine for certain Algee 

 (Chapter III.) which tangle themselves about it in fine 

 green threads, appear to favor it, and may often be 

 seen with the naked eye if the single frond is placed 

 in water above a white surface. 



