REVIEW UF Tin; lu»nK _".»•> 



wliioli wratlieriiiK procefiisT Dot>a w«>Hthi>riii(; act on Hurfftcea that 

 art« ill (^I'ticral Ifvel an well as on tlioNo thiit are iiioiincttf I'upils 

 sliould briiiR ill a Btone or brii-k or some olluT piece of mineral 

 niat«Tiul that shows tha eJTiet of weallu'rintj. Why are pebbles 

 rouiule<li What h:iH luM-oiiie i>f the parti<-le» that have liJHappeared 

 from theiuf Why may wealiieriiiff proceed less slowly on level 

 areas than on steep hills f Why do mountains and hills tend to 

 beoutue rounded f Why are some mountain peaks sharp and 

 others rouinb-dT After weatherin;j has proceeded, how are the 

 detached particles distribute«lf 



How do plants become a(;eiit8 in the formation of soil! Where 

 do lichuus growf How do roots act in the inakinfj of soil! How 

 do animals contribute to the making of soils! What is uiulerstood 

 by chemical action (.'JOlT Let the teacher or pupil read sotiie of 

 the extracts from Darwin's book on "Vegetable Mold." explaining 

 how it is that the earth-worm contributes to the formation of soil. 

 Are there any soils in whi<'li or>janic matter predominates; if so, 

 where are they formed, and howT What is humusf How does it 

 modify the texture and color of soilsf What is tliH value of humus 

 i:i.l)t How may the farmer secure buniiis for his land f How im- 

 portant do you consider humus to be in the fiirininp of your nei^h- 

 borlioodf What is n miero-o^^anism T How do inicro-orpanisms benefit 

 soils or contribute to the prowlh of plants! Do you understand 

 that the soil is n scene of life as well n collection of materials? 



How is soil transported and laid down? How may stones be 

 a source of benefit to land? What are the chief apencies by means 

 of which soils have be««n trannportedf What soils partake most 

 elosely of the nature of the bed ro.-k on which they lief Kxplain 

 how A stream becomes a transporter of soil. What is muddy 

 wnterT Let the pupil illustrate what there is in muddy water. 

 What are glaeierst What has been their effect on the soil on a 

 large part of northeastern North AmericaT Determine whether 

 the soils of your region have been modified by the •otioo of 

 glacieis. What inflncnce has the wind In transporting sollst 

 Illustrate from the sand storms of the plains and deserts. Is there 

 dust in the atmosphere! If so, what is it and how mar it he 

 detected! 



