424 TEXTBOOK OF BOTANY 



2. If timber is being cut, make a study of the various processes 

 concerned. Is there much waste ? What might be done with the 

 parts of the trees that are not used? How are the logs handled 

 after the trees are cut down ? 



3. A study may also be made of shade and ornamental trees, 

 special attention being paid to those which are of economic im- 

 portance. 



4. A saw mill should be visited if possible. Even a portable mill 

 is well worth visiting. Follow the log from the time it enters until 

 it leaves the mill. What is meant by straight cut lumber ? Quarter- 

 sawed lumber ? 



5. A visit to a lumber yard should be made. Note what kinds 

 of wood are found. What names are given to the various kinds of 

 lumber? For what are the different kinds used? A furniture 

 store or a cabinet maker's shop will show some of the more valuable 

 woods. Where are they obtained ? For what are they used ? 



6. Visit if possible some wood-using industry such as a chair 

 or furniture factory, box factory, wagon works, or pulp mill ; ob- 

 serve the woods used and the processes employed in the making 

 of the finished product. 



CHAPTER XXIII 



If there is opportunity to do so, the class should visit a greenhouse 

 or other place where plant-breeding is being done. Notice whether 

 or not all new plants are grown from seeds. If not, what methods 

 of multiplication are used? Do all the seeds of any plant grow 

 into plants exactly like the parent? What methods are used in 

 crossing plants ? What is the object of crossing ? What methods 

 of selection are in use? If new races produced by selection are 

 available, compare them with the parent races. What improve- 

 ment has been brought about by selection ? Lists may be made by 

 pupils of such varieties as they find in cultivation of the wheat, pea, 

 tomato, potato, or other common plant. What are the advantages 

 of each variety? Why is it worth while to have more than one 

 variety of a particular species ? What can you find out about the 

 history of common cultivated varieties? Have full records gener- 

 ally been kept in the past of plant-breeding work ? 



