35° 



George E. Nichols, 



periodic, lakes or swamps. Permanent and periodic lakes and 

 swamps, as related to topography and ground water level, have 

 been fully discussed in the writer's paper referred to above ('15, 

 pp. 172-175). 



b. THE ASSOCIATION-COMPLEXES OF WELL-DRAINED LAKES AND 



PONDS 



The association-types of permanent lakes. — Freshwater Lake 

 (Fig. 41) and Warren Lake, at Ingonish, may be taken as repre- 

 sentative examples of fairly large, well-drained lakes. Except 

 for Chara and various algae there is little vegetation below a 

 depth of six feet. The majority of aquatic plants grow best in 

 water less than three feet deep. Along sandy shores, which are 

 the prevailing type in both ponds, the following aquatic species 

 are more or less abundant. 



Chara sp. 

 Fontinalis sp. 



Iso'ctes echinospora Braunii 

 Sparganium angustifolium 

 Potamogeton Oakesianus 

 Potamogeton heterophyllus 

 Potamogeton hupleuroides 

 Glyceria horealis 

 Scirpns suhterminalis 



Eleocharis palusiris vigens 

 Scirpns americanns 

 Junciis militaris 

 Nymphaea advena 

 Ranunculus Flammula rcptans 

 Myriophyllum humilis 

 Nymphoides lacunosum 

 Eriocaulon septangulare 

 Lobelia Dortmanna 



Nymphaea and Nymphoides are the commoner forms in the 

 deeper shallows. Eriocaulon often forms a bright green carpet 

 on the bottom in water three or more feet deep, but seldom 

 flowers where it is more than a foot deep: Ranunculus forms 

 similar carpets in shallow water, but flowers only on the shore. 

 In places Juncus and Isoetes grow in profusion. But for the 

 most part the sandy bottom is only sparsely covered by vege- 

 tation. It might be added that Carcx aquatilis, not noted in 

 either of these lakes, is a frequent form along the shores of low- 

 land lakes, locally giving rise to marshy marginal swamps 

 similar to those to be described later in connection with lakes in 

 the highlands. 



The narrow sandy beach, between high and low water marks, 

 supports a scanty growth of herbaceous species, among them 



