344 



AGRICULTURE ON THE PACIFIC SLOPE 



There are two reasons why the grain is bent or twisted 

 at the crotch. One is that the grain must bend around 

 the branch. " Another is that the wood has less space to 



grow in each year as 

 the crotch fills up. 

 As will be seen by 

 the figure, the wood 

 had during the first 

 year a great deal 

 more space for 

 growth than during 

 the last year. As it 

 cannot spread out, it 

 tends to grow thicker 

 in the crotch, and it 

 will be noticed that 

 the annual rings are 

 thicker here than 

 elsewhere. It also 

 tends to form a 

 hump, as shown in 

 the figure. Beneath 

 the branch the same 

 thing is seen, though to a less extent. For the same 

 reason any bend or hollow tends to fill up, and so 

 both trunk and branches get straighter as they grow 

 older. The grain in such places is often wavy, as 

 seen in curly redwood. 



FIG. 180. A branch split open to show how 

 the grain of the wood runs. 



