10 



1)0 niontioiiod tlic names of Lea, Biiuioy, T.owis, Tiyoii, 

 Antliony, Ilaldoinaii, (iotild, Cooper, Conrad. And not least 

 among them all, I)f. AVm. Stimpson, late .secretary of tlie 

 Chicago Academy of Science. There arc many others, Lut 

 most of those I liave mentioned are better known to nie 

 through their Avorks on our land and fresh-water shells. 7\11 

 of the above have published numerous papers upon our 

 Mollusca in the proceedings of various scientific societies. 

 These are, however, inaccessible to the general reader on 

 account of tlieir cost, and I might say, also, undesirable to 

 most 2)eople by reason of their dryness. It takes a true nat- 

 uralist to appreciate them. Therefore, very few know anything 

 about the important Avork being done by our scientific associ- 

 ations, except wliat they get second-hand through tlie medi- 

 um of some cheap ])opular publication, — a ])roof, why, in view 

 of tlie growing interest felt in the progress of scientifit; research 

 in this country, Ave should have in every state, Avorks on local 

 natural history, such as would be adapted to the use of schools 

 and of young investigators. 



ON THE DISTKIBUTIOX OF SPECIES IN LA SALLE COUNTY. 

 The Helices, or land-snails, Avere formerly very abundant 

 in all the timbered sections and along the rivers and creck.s. 

 The Quaternary deposits are also filled Avith the dead shells. 

 But the encroachments of the " Old Settlers'" upon tho forests 

 have greatly reduced the numbers of living specimens Avithin 

 the last twenty years; and Ave may anticipate the time Avhen 

 the last snail Avill disappear from our geographical limits. 

 The favorite homo of the snail family is the deep shade of 

 some forest retreat. In this country they are seldom found else- 

 where, Avith perhaps the exception of a few species. And yet 

 I remember the time, some tAventy years ago, before agricul- 

 ture had invaded our i)rairies, and Avhen there Avas a dense 

 growth of vegetation, that snails Avere quite common in situ- 

 ations remote from the timber regions. I frequently found 

 them in my father's garden. And this Avas my first acquaint- 

 ance Avith that interesting family. I was a mere lad at that 

 ti?ne, and could see no possible use for the nasty, slimy, things. 



