116 Modern Business Geography 1. What influence do you think these conditions have upon the abundance and nature of the primary products, and thus upon the growth of sea- ports? Explain. 2. What influence do they have upon trade with the interior? 3. Table 7 (page 336) gives the chief exports of South America in the order of their value and shows what countries export them. Which of these come from hot, tropical lowlands? How important are they? Table 6 (page 335) gives the chief cities of South America. Arrange them in order of size. How many are found on the north and northeast coast? How do these stand as to size? How many and of what size are the cities south of latitude 20° S? Because of the scantiness and relative inefficiency of their inhabit- ants, the tropical forests furnish few primary products for com- merce, even though their possible resources are large. 5. What fraction of the entire South American seacoast is therefore un- favorable to the growth of seaports? Returning to southern Ecuador, let us examine the coast from there to Valparaiso in Chile. This almost rainless coast is bordered by a desert, except where irrigation is carried on by means of streams from the Andes. 6. What fraction of the total western coastline is bordered by desert? 7. Explain why there is so little rain on the west coast. 8. What influence does this desert have on primary production? upon the growth of seaports? 9. How many of the products of Table 7 (page 336) come from deserts? 10. How many of the cities of Table 6 (page 335) are found on this coast? Now examine the rest of the west coast of South America. 11. How many of the cities of Table 6 are found south of latitude 45° 12. What does this lead you to infer as to the importance of the primary products of this far southern part of South America? Turn next to the west coast between 30° and 45° south of the equa- tor, and to the east coast from the coffee plateaus of Brazil in latitude 20° to latitude 45°. 13. Which of the chief primary products come from this section ? 14. How many of the chief cities are located here ? Certain other conditions also help to make the southern re- gion highly productive. One is the presence of Europeans; for this is the part of South America where people of European ancestry largely outnumber the colored races.