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ceous kinds ; and upon these still others prey, so that flesh-eating ani- 

 mals make up the most conspicuous classes of marine animals. Quite 

 otherwise are the conditions on land, where no air current carries food 

 to the hungry mouths of animals. Plants with roots in the soil and 

 stems in the air are able, however, to secure their food from the cir- 

 culating medium, but being themselves fixed, they are easy prey to 

 animals — both the sedentary kinds, which live in or upon the plant tis- 

 sues, and the active wandering kinds, which forage over large areas. 

 The predaceous animals, either by active mind or body, must secure 

 their food from the plant-feeding kinds. The great expanses of grass- 

 land and forest tend to be devastated by a vast army of animals which 

 far outnumber the predaceous kinds. The conditions of life, there- 

 fore, found upon grassland areas, like the prairie, and in the forest, 

 are to the farthest possible extent removed from those found in the 

 sea. This, then, is one of the most fundamental contrasts in the con- 

 ditions of existence encountered by animals. 



These considerations naturally raise the question to what extent 

 and in what particular manner does land vegetation influence animal 

 life ? Does a change in the vegetation as great as that between the for- 

 est and the prairie have a marked influence upon animals? In the 

 Charleston region we have just such a difference in the vegetation. 



Many years ago Bates pointed out repeatedly in his "The Natural- 

 ist on the River Amazons" that the animals of that densely forested 

 region were to a marked degree distinctly arboreal and "adapted" to a 

 forest life. In most densely forested regions like conditions probably 

 prevail, and to a corresponding degree open lands harbor animals 

 equally characteristic and as truly terrestrial in habits. The contrast 

 between the conditions of life in the open and in the forest is one of 

 the most fundamental environmental conditions upon land. The sig- 

 nificance of this contrast seems to have been realized only in part. The 

 prairies or grasslands are representative of only one kind of open ; 

 they are caused by many kinds of factors limiting the extension of 

 forests. Open places are formed by lakes, ponds, and swamps ; by the 

 avenues through forests formed by different kinds of streams, as 

 brooks, creeks, and rivers ; by the small amount of soil on rock sur- 

 faces; and by still other kinds of limiting influences, such as the sea, 

 severe climate, and altitude. Among almost all of the major taxo- 

 nomic groups of land animals is seen the independent origin and pres- 

 ervation of animals suited for life in the forest; this clearly points to 

 the extensive influence and antiquity of this environment. The same 

 is true of animals living in the open. But to assume that it is solely 

 the kinds of forest trees serving as food for animals, or the cor- 

 responding kinds of vegetation in the open, which determines whether 



