252 Roosevelt Wild Life Bulletin 



land ; also, an expanded part of a river." Also, " when a body of 

 ' standing- water is so shallow that aquatic plants grow in most of it, 

 it is usually called a pond; when the pond is mostly filled with 

 vegetation it becomes a marsh. Lake basins have originated in 

 many ways, but mostly through glaciation." A pond is defined as 

 " A body of water naturally or artificially confined and usually 

 smaller than a lake; in England, usually, except locally, a body of 

 water artificially confined." 



In some localities comparatively large bodies of water which used 

 to be called ponds are now lakes, and the name lake is often locally 

 given to inconsiderable " bodies of standing water in a depression 

 in the land." The largest inland body of water in Maine, Moosehead 

 Lake, has always been known as a lake, but the second in size, now 

 Sebago Lake, was once " Sebago Pond." A small body of water 

 near Portland, formerly " Duck Pond " is now " Highland Lake." 

 Thus the terms lake and pond have become quite generally synony- 

 mous, and in this discussion they must be so regarded. 



Lakes and ponds vary greatly in character in different sections of 

 the country and often in their different parts (figures 28, 29). In 

 the northeastern states the majority of " considerable bodies of 

 standing water in a depression of the land " are glacial and post- 

 glacial in origin. In many respects, although greatly differing in 

 size, they are very similar in character. There are also variable 

 extents of river expansions, as well as considerable bodies of water 

 set off from a river, lagoon-like in situation but too large to be 

 called lagoons, that have been termed lakes. 



While this paper does not aim to include artificial ponds in its 

 discussion, reference should be made to certain bodies of water of 

 variable size and character which perhaps may be called semi-artifi- 

 cial ponds. For those who desire information on artificial ponds 

 reference should be made to Embody ('15), Johnson and Stapleton 

 (/15), and Titcomb ('23). Ponds of this kind are those which have 

 been formed by damming a stream (figures 30, 31), but which have 

 developed into or remained in a more or less wild state, such as 

 some millponds, water storage reservoirs, ice ponds, or beaver 

 ponds, or they may have been originally intended for fish ponds. 

 They vary in size 'and character according to circumstances, and in 

 general may be much like some other natural ponds. Some well- 

 known lakes and ponds were thus formed or increased in size by 

 having l)een dammed by the action of ice or floods in glacial or post- 

 gkicial times. These, however, are all under the head of natural 

 lakes and ponds. The history of all recent semi-artificial ponds 

 subsequent to the formation of dams has been much the same, de- 

 pending upon the obtaining local conditions. Nearly always the 

 result has been more or less rise in the temperature of the water. 

 Often water plants accumulate in shallow water, and always there 

 is a gradual accumulation of silt and debris in shallow water at the 

 mouths of inflowing streams which gradually encroach upon the 

 depth of the pond, so that sometimes the bottom thus formed rises 



