2 NATURAL HISTORY 



fail to find an interest in this approach to natural history. Why, for 

 example, do eertaiii kinds of animals live in the swift water of trout 

 streams, while different ones are associated with plants in a quiet 

 pond? Why are the types of life found along the seashore so unlike 

 those around the edge of an inland lake? Why do forest trees grow 

 tall in the dense woodland, more spreading in the open, and stunted 

 near the tops of mountains? These and hundreds of like questions 

 can be answered truthfully with the background afforded by the 

 science of ecology. 



Ecology of a Typical Region ^ 



New England scenery is characterized by rounded granite hills, 

 often heavily wooded with second or even third growth. In the 

 hollows surrounded by these hills nestle little lakes, bodies of water 

 varying in area from a few hundred square feet of surface to many 

 scores or even square miles in extent. 



A survey of the inhabitants of one of these smaller lakes, chosen as a 

 typical example, reveals relatively few fish and fewer plants in the 

 open water. Nearer shore are found unmistakable zoning of plants 

 and animals, depending on whether the shore is rocky, sandy, or 

 muddy. In sheltered bays having a bottom of soft mud are found 

 numbers of pond lilies and other aquatic plants, which give shelter 

 to pickerel, bass, and smaller fish, as well as a vast array of small 

 crustaceans, insect larvae, and microscopic plants and animals. 



Part of the lake shore is a sandy beach, at one end of which a slug- 

 gish stream, after meandering through a meadow, empties into the 

 lake. This constitutes quite a typical environment and will yield 

 abundant material if searched carefully. 



The edge of the lake bordering on the beach contains relatively 

 few plants and animals. It is exposed to the wind and consequently 

 to wavelets which cause more or less movement of the loose sand, thus 

 giving slight protection to living things. We find here almost no 



' BOOKS USEFUL FOR FIELD WORK 



Downing, Our Living World, Longmans, Green, 1924. 



Johnson and Snook, Seashore Animals of the Pacific Coast, Maemillan, 1927. 



Lntz, Field Book of Insects, Putnam, 1921. 



Mann and Hastings, Out of Doors, Holt, 19.32. 



Morgan, Field Book of Ponds and Streams, Putnam, 19.30. 



Needhani and Needham, Guide to the Study of Fresh Water Biology, 3rd ed., Comstock Publ. Co., 



193.-). 

 Weaver and Clement, Plant Ecology, McGraw-Hill, 1929. 



