viii 
PAGE 
Weod preservation and tie-treating plants in Illinois........... 337 
Timber USEC ean! COA MINES, = roie ne sekorclsyey asaya sto eiclsyal sie a's) crane sasha eae 340 
Ill. Forest problems: ; 
OSA SS eeetek Gicctinns. tilovaitie biedeya store steno re niavace m Slere%s, 6/2 a eveeneaistele te See 342 
Directieiects OL -fTeSs hei ctatewte cs brsses estes sie Gis ss ee Oe op) se 342 
ENP ECV CO MLODEOOUCULON) cc sersrete ave Gre eitiers. oie Gas srs) se, obveie sae ee 343 
Pnyury. tO" BRGY SOM ee sfc aceis 0c wise cee leivals acvene, sovls &o atare sete eae eee 343 
Injury to productive power of the forest.....5..5..:0.. cm cele ien 344 
Effect of severe burning upon young stands..............+.e2e0ee 346 
[BIN OSEOTUM Sse ste a taraciasal tet cre ietscefevon anaes s:ov aos tescuh a vous: oats ete sured) arenene ten tena 346 
GRIT a ate as ae teaaioee ete ave Ma gsin esata avcionsys/ ove. cuss 'seaslate (el othe ovelsh cicada eRe ean 347 
RV, “MOrest. pOlley and! MANALECMENT .:. o.< cie «mice nie oe naive letter ee aan nea 348 
Ubatswipollenaslaintsal os) leone oe oomoen OD OoOadoonrn oa Cdossocanc oO aoss 348 
Outline of proposed fire-protection system for upland timber belt.. 348 
Therso-called farm (WOOULOES). «0.0. eicie. 0. sins» @ olere ohejeleehein!>ieeieehtet enter 349 
The OVETrHOW DOttOMIATGS)..2../5 ec orci eters n ose 2's o acaye mielte te, erepetene ohne tera 350 
We Voliime anid! ‘Srowith "Studies ss. <0 cl ete1s i: <.;0.05%severallauere! sieleaelel aisha taeeeaanele 350 
SSG Sry ATA SAG tela c avaiable sve el vin'»is/erecele la; «in ars 8ta) ciaie aievotesecskahel ete ete teneeamamn 351 
PU DITOR ADU: isctetsees axe enol cet ole «01 se) ota} aisva ote araysie ate te tapas lerate theta) cetera ean 354 
Appendix: 
Volume tables for leading species, and taper and growth apie and 
graphs for white and black oak..................... POCA o ¢ 357 
ARTICLE IX. THE DETERMINATION OF HYDROGEN ION CON- 
CENTRATION IN CONNECTION WITH FRESH-WATER BIOLOG- 
ICAL STUDIES. BY VICTOR E. SHELFORD. (1 Trext-ricure, 1 
GRAPTED)) TREBRUABY: 1928555 ite: os eileen ersyeieieye » ns) e-ayeievaparelelorateletal eal Eee 379-395 
TELE PIGLAONE 5 coe ace cytes Perper at avp © sal ecepinyice aoe ica a: oahxval ecalovatle elaine Senha eR Rn ean 379 
Methods of determining H ion concentration (pH)................... 380 
The influence of hydrogen ion concentration on fertilization, develop- 
ment, growth, and survival in water deficient in oxygen.......... 381 
Reactions of fish to differences in hydrogen ion concentrations....... 385 
An examination of certain Illinois waters with special reference "to 
hy @rogsens TON CONGEMULATION .. «ceric ieee oes aie) cine ole oeeloielei sve sere ee 386 
General relations of hydrogen ion concentration to other factors...... 388 
DIscussion and SuMMALyY. Of TESUITS . oic.ci..01 nies se ace acre stelete enslereteneeeotemane 391 
GOTEGTU SEONG ey ratere lore elerctolete. crete sy bi sjuetol deste Ww niiele sel sls eve 12 ete Toros at net ae oe 392 
WWGkNGWICASMENCS! Miele eieic asics + ole vie eyece.w aise obs 01.100 Ble area seer ee eee 394 
Bipliosraplyeuc ye coe cya + cheaierse\s sare, c'eyoreva eve /e ls alcis/aycte, eee siarenerer eters enter 394 
ARTICLE X. ON THE NUMBERS AND LOCAL DISTRIBUTION OF 
ILLINOIS LAND BIRDS OF THE OPEN COUNTRY IN WINTER, 
SPRING, AND FALL. BY STEPHEN A. FORBES AND ALFRED 
OAGROSS: MOGTOBER, G28). ,<je.2 rele aixc\ers [al oferantvale sleeve <tcrerdtchetare ene 397-453 
Thea winter Dirdss ence eiea ce cake oie ee oi eciebsiee soars eresee Oe eee 397 
inevdata Wy SCCuOnS OL UME’ SLALC io)a ereratetrayapatorciaiste efereler nels aie ee ere 400 
Residence classes and their seasonal movements..................... 402 ~ 
‘ 
ee 
