108 ILLINOIS ACADEMY OF SCIENCE. 



had been attacked by a fungus, whose myceHum and sex organs 

 were plainly visible. 



• The full paper, with illustrations, is published in the Botanical 

 Gazette 51: 449-453. pis. 28, 29, figs. 3. 1911. 



POST-GLACIAL LIFE OF WILMETTE BAY, GLACIAL 

 LAKE CHICAGO. 



By Frank Collins Baker. 



The Chicago Academy of Sciences. 



About two years ago the writer^ announced the discovery of 

 certain strata west of Bowmanville, Chicago, which quite fully 

 revealed the faunas as well as the history of Glacial Lake Chicago, 

 During 1910 a complete biological and stratigraphical survey was 

 made throughout the length of the drainage canal (over eight 

 miles) and sixty-three separate sections were made, besides sev- 

 eral hundred additional examinations between these section sta- 

 tions. The information obtained in a measure corroborates the 

 statements set forth in the preliminary announcement. It also 

 makes it evident that several statements made therein need some 

 modification. The deposits referred to represent the floor of 

 Glacial Lake Chicago and the variation in these strata quite vividly 

 reflect the changes which took place from the time the glacial 

 waters first appeared until the formation of the present Lake 

 Michigan. As the general history of the great lakes is so well 

 known, it will not be referred to here.^ 



The interpretation of these deposits, viewed in the light of 

 later and more extensive information, may be outlined as follows : 

 Above the bowlder clay or till there is a bed of sand from two 

 to twelve inches in thickness (Fig. 1). This represents the Glen- 

 wood stage of Lake Chicago and no Hfe is present, as would be 

 expected. During the Glenwood stage the lake stood at from 

 fifty to sixty feet above the present level of Lake Michigan. This 

 places the shore line between the 630-640 foot contour lines. It 



iScience, n. s., XXXI, No. 801, May, 1910, p. 715. 



^See the following works where the history is very fully worked out : 



The Geography of Chicago and Its Environs, by Rollin D. Salisbury and W. C. 

 Alden. Bull. Geog. Soc, Chicago, No. 1, 1899. 



Geological Atlas of the United States, Chicago Folio, No. 81, by V/. C. Alden, 

 1902. 



Physical Geography of the Evanston-Waukegan Region, by W. W. Atwood and 

 J. W. Goldthwait, Bull. 7, 111. State Geol. Survey, 1908. The Pleistocene Features 

 and Deposits of the Chicago Area, by Frank Leverett, Chi. Acad. Sci., Bull. II, 

 Geol. & Nat. Hist. Surv., 1897. 



