The author, several years ag'o, having* collected 

 more than 100 plants not in Prof. Bolt wood's cata- 

 log-ue proposed to himself a revision of that work, and 

 was urg-ed by friends to undertake the work. But ill 

 health and unfortunate business adventures, prevented 

 its immediate execution, and moreover he found the 

 task to require an amount of labor much greater than 

 he had contemplated, and w^ant of health led to an 

 abandonment of the work after much time and atten- 

 tion had been gfiven to it and the manuscript for about 

 half of it had been prepared. 



The work was ag*ain taken up at the earnest solic- 

 itation of Prof . Williams, to be ag-ain abandoned as we 

 thoug-ht definitely, but ag-ain Prof. Williams urg-ed 

 its completion, and under many, and not small difficul- 

 ties and discourag-ements, the Botany was about ready 

 for the press when we found it necessary to rearrang-e 

 and revise it to mai^e it ag'ree with the 6tli edition of 

 Gray's Manual. In the mean time w^e had enlarged 

 our plan and had part of the matter for the other sec- 

 tions of the w^ork prepared. 



About this time, we opened correspondence with 

 W. W. Calkins, attorney-at-law, of Chicag'o, form- 

 erly a resident of Deer Park Tp. , who most unex- 

 pectedly to us, placed at our disposal his work on the 

 Ivand and Fresh Water Shells of La Salle County, 

 and a little later, oflFered to write the section on Lich- 

 ens, and Prof. Williams kindly authorized us to use 

 any part, and as much of Baldv\'in's History of La 

 Salle County, and Dr. Evans' Vermillion River Coal 

 Field, of which he is joint author, a privilege that we 

 have found of much value. 



For tlielchthvolog-y and Kntomolog-}^ we ha ve con- 

 sulted the Reports of the Indiana Geolog-ical Survey, 

 Jorden,s Manual of Vertebrates, 4th edition, imprint: 

 Jansen McClurg- & Co., 1884; Tenney's Natural 

 History, imprint: Chas. Scribner & Co., 1866, as 

 w^ell as for other sections. Also Tryon's Systematic 

 Conchologfy; and other standard works. 



The author is w^ell aware that he has in most of 

 this lield g-one over the surface, that much remains to 



