1.54 



AqiKitic Organisms 



water. Increase is by budding and outgrowth of new 

 lobes from pre-existing thalli. Flowering and seed 

 production are of rare occurrence. 



The water lily- 

 family includes 

 the more con- 

 spicuous of the 

 broad-leaved 

 aquatics, which 

 pre-empt the 

 rich bottom mud 

 with stout root 

 stocks , and 

 heavily shade 

 the water with 

 large shield- 

 shaped leaves, 

 either floating 

 upon the sur- 

 face, as in the 

 water shield and 

 water hlies or 

 lifted somewhat 

 aboA^eit.asinthe 

 spatterdock and 

 the lotus. They 

 are long-lived 

 perennials, re- 

 quiring a rich 

 muck soil to root 

 in. These are 



Fig. 64. Leaf-whorls. distinguished 



/l.and r ihr-hornwort (Cwa/o/j/iWtem); B, the water milfoil for the beaUtV 



(Mynofhyllum). .1 is an old leaf, the upper half normally ^^'^^^^ UCaui,_y 



covered with algicanrl s:lt; the lower half cleaned, save for a aud fraP'ranCe OI 



closely adherent dwelling-tube of a midge larva m the fork at ' . \f^ d-liCC UL 



the ngnt. C. 15 a youiiy partly expanded leaf whorl from the their floWCrS. 



