472 



NATURALIST'S GUIDE TO THE AMERICAS 



zibethica), marsh hawk, marsh wrens, 

 red-winged blackbird, dragonflies, and 

 mosquitoes. In the cypress swamps 

 in the southern part of the state occurred 

 the swamp rabbit (Sylvilagus aquaticus). 

 In northeastern Illinois were numerous 

 swamps and a few northern bogs. In 

 the latter grew the tamarack {Larix 

 laricina), mountain ash (Pynis ameri- 

 cana), pitcher plant (Sarracenia pur- 

 purea), cranberry {Vaccinium macro- 

 carpon), and there lived numerous 

 insects with northern affinities such as 

 the tipulids {Nephrotoma sphagnicola 

 and Tipula senega) . Swampy areas also 

 occurred in the bottomlands along the 

 water courses and were caused by the 

 overflow during the early spring floods. 

 The extensiveness of the rivers and 

 lakes, particularly the former, enabled 

 this state to support a varied and abun- 

 dant aquatic and semi-aquatic biota. 

 The lake district of Illinois was essen- 

 tially in the northeastern part of the 

 state and here there are about 20 lakes 

 one mi. or more in length. These are 

 of glacial origin. The larger rivers and 

 their tributaries were more evenly 

 distributed throughout the state. Both 

 the rivers and lakes of Illinois were 

 originally well stocked with various 

 kinds of fresh water fish, and aquatic 

 insects and mollusks occurred in abun- 

 dance. These areas or their margins 

 also supported muskrat and mink, as 

 well as numerous water loving birds. 



4. PRESENT BIOTA 



The original biota of Illinois is very 

 seriously disturbed. The game, both 

 large and small, has been very largely 

 destroyed, except in the Ozark Highland 

 in the southern part of the state. The 

 bison, black bear, elk, snowshoe hare 

 (Lepus americanus), beaver {Castor 

 canadensis), and gray fox {Urocyon 

 cinereoargenteus) , had quite generally 

 disappeared before or about 1850. 



While the area now occupied by most 

 of the plant and animal types just 

 enumerated, and many others neces- 

 sarily left out, is very much curtailed 

 in contrast with the display of a century 



and a half ago, there still exisi; ample 

 examples of every major habitat except 

 the prairie which once was the most 

 representative of them all. Since very 

 few original tracts of prairie now remain, 

 it is of the most urgent importance that 

 some be set aside in perpetuity before 

 it is forever too late. 



Extensive drainage has reduced much 

 of the area formerly of swamp and 

 bayous character, while stream pollu- 

 tion has been responsible for the change 

 in the biota of otherwise more perma- 

 nent habitats — the larger streams and 

 rivers. Notably, the original flora and 

 fauna of the Upper Illinois River is 

 almost exterminated by Chicago sewage. 



II. NATURAL AREAS 

 A. CHICAGO DISTRICT 



1. Prairie 



*Riverside Prairie. (Cook County 

 Preserves.) About 10 acres near the 

 Desplaines River; typical mesophytic 

 prairie; general aspect characteristic 

 of large areas in Illinois oak grove 

 savanna. See Bryant's poem "The 

 Prairies." 630-650 ft. altitude, level. 

 (See frontispiece.) 



Chicago, 12 mi. west, C. B. & Q. R. 

 R., or La Grande Electric; § mi. N.W. 

 from (W). Riverside, 111.— F. E. 

 Shelf or d. 



2. Deciduous forest of the Cook County 

 district 



*Cook County Forest Preserves. In- 

 cludes deciduous forest, flood plain, 

 ravines, hills, swamps, ponds, rivers, 

 and springs. There are at present 

 24,806 acres devoted to such purposes 

 which have been acquired since 1913, 

 and according to Chief Forester Ransom 

 H. Kennicott there are 30,000 acres 

 available for reservation as forests. It 

 must be remembered, of course, that 

 not all of this is wooded, but that some 

 is taken up by golf courses, baseball 

 diamonds, tennis courts, and open 

 spaces of various kinds. The Forest 

 Preserve District has also acquired 

 title to more than 260 acres of the 



