390 



ECOLOGY. 



for a number of 

 years when the 

 earlier zones were 

 floating accounts 

 for the circular ele- 

 vation and atoll 

 formation. 



703. A black- 

 spruce moor. A 

 somewhat similar 

 but more advanced 

 plant formation oc- 

 curs east of Free- 

 ville, N. Y., and 

 about nine miles 

 distant from Ithaca. 

 The center of the 

 basin, which was 

 perhaps shallower 

 than the former 

 one, has become 

 completely filled, 

 and all of the cen- 

 tral formation is 

 more elevated than 

 the margin by the 

 shore of the basin. 

 All around the mar- 

 gin in wet weather 

 the ground is more 

 or less submerged, 

 while all the central 

 portion is so ele- 

 vated that the nu- 

 merous stools or 

 hummocks of 



