miller] the U\4Y of a caterpillar 85 



stream. When the stream has cut down to a certain level and 

 changes its course the new level which it makes will form a 

 terrace. Another way in which terraces are made is found where 

 the underlying layers of rock are horizontal. The river can not cut 

 so quickly through the second layer of hard rock as it could 

 through the first layer which was soft. The river in that case 

 may cut down more rapidly than sideways and so form a terrace. 



The main place of deposition of the Thornton stream is on 

 the valley bottom and takes the form of islands and sand bars. 

 When a branch, or some other obstacle, is caught, the water in 

 striking it is checked, and drops some of its load. As the stream 

 drops its sediment around the branch, the obstacle grows and 

 more water is checked thus an island may be formed. 



\\'hen a stream is overloaded, or its velocity is checked it 

 must drop some of the load in the stream bed. This is how sand- 

 bars are made. 



Natural levees are formed in tiood time. W^hen the stream 

 overflows its banks and still water is standing on either side of 

 the main channel, the swift loaded current strikes the still water, 

 its velocity is checked and it drops its load right on the edge of the 

 main channel. As a stream cuts on the outside of a bend it de- 

 posits on the inside and so land is formed on the inside of a bend. 



There are many causes of stream deposition, but the main 

 cause of the Thornton river's deposition is loss of velocity. 



A'egetation is a great hindrance to erosion. The roots of 

 trees hold the soil, and even grass makes erosion more difficult. 

 At one place, where the river had washed away the soil in widen- 

 ing its valley, only the soil around the roots of the trees re- 

 mained. 



The Way of a Caterpillar 



Ellen Robertson-Miller. 



It is worth while to stop occasionally and take note of how 

 the insects manage to get on in a world filled with enemies. 



We soon learn that every species has its special methods of 

 evading or combating animals bent upon its destruction — and 

 the methods used often prove a fascinating study. I have found 

 the behavior of caterpillars especially interesting. 



Take for example, the common Mocha-stone, Tch-thy-u-ra 

 in-clu-sa. These lavae live in family groups, and frequently in 

 rather crowded quarters, but they seem never to show irritability, 

 no matter how much crawling over and under each other occurs. 



The nests of the Mocha-stone may be seen on poplar and 



