1897.] NATURAL SCIENCES OF PHILADELPHIA. 431 



" Prof. Karpinsky states that every one of these streams is divisible 

 into three courses — a fresh-vvater-lake-region upper course, a gorge- 

 region middle course, and a meander-flood-plain-region lower course. 

 Oawl Trtoa 



7 



PUn ot Pr«VirMO|e +or ^ny +nbatr*ry of- the. Ir+y&ch 

 Draininq Asiatic Slope of CJmI&. 



Soer\ Level 



o 





zn-H~- 



5e<-* Level 



X a. 

 <0 



/jrom s>ke-rch by Pro)-. Miller") 

 > "for +his> p*per- / 



Fig. 3. 



It is the peculiarities of the upper and middle courses that here 

 demand explanation." 



