270 



Tlic loiiinioii watcrci'css (l{i)ii|i;i iiastui-thim L.) was abundant in 

 (iuarry B, liavini:- Ikhmi cMrricd in l)y tlic little stream from the north. lis 

 spread, however, was vciy slow, srciuinjily dependent on the amount of 

 surface soil lai-ricd in liy tlio sti-cani. since it ditl not thrive in the lime- 

 stone soil. 



A few plants of llie button busli (Ceplialanlhus occidentalis L.i were 

 found ai'ound. the pnnd in iinariy ('. 



i-iff. 4. 



A sunimaiy ;;ives the followinu conchisicnis: il) the liist plants a;e 

 the algae in great vai-iety and aliniidaiice. (l*i A very few lichens. (3) A 

 few mosses. i4) E(iuiselu;n very lare: the soil not suited to its growth, 

 (o) Typical hydrophyte societies in tlie pnnds. tlie Typha latifolia lieing 

 most conspicuous. Tlie ixnids sh.wiy encioaclied njion by the sedges and 

 grasses: These plants foi-in a soil for Hie many dicotyledons which are 



