''flowers'' on its interwoven twigs has been dredged 

 from a depth of over one thousand feet. Along the 

 rocky shores of the United States, Canada and the 

 coasts of England and France there are found simple 

 corals in the form of tiny individual cups. None of 

 these cold water corals, however, grows so actively or 

 to such a size as the reef corals of the tropics and their 

 form IS always small and delicate rather than large and 

 massive. 



True reef corals, which individually may reach a 

 size of several feet across, are never found in great 

 depths or in cold water, but always in fairly shallow 

 depths near tropical shores. Even in the tropics they are 

 not found universally, but only in certain well defined 

 areas. These areas are situated within a belt roughly 

 bounded by the tropics of Cancer and Capricorn, imagi- 

 nary lines which are drawn around the earth 23 V2 

 degrees north and south of the equator and which mark 

 the northern and southern limits of the sun's movement 

 during the year. Within this 3,000 mile belt coral reefs 

 are abundant on the eastern shores of continents such 

 as the West Indian Islands and Brazil on the American 

 continent, and from the Red Sea to Madagascar on the 

 eastern side of the African continent. They form a 

 gigantic series of barriers known as the Great Barrier 

 Reef off the northeastern shores of Australia and are 

 dangerous to navigation throughout the South Seas and 

 the tropical Pacific Islands. Coral reefs lie under the 

 breakers off island shores in the Indian Ocean and in 

 the Atlantic are even found as far north as Bermuda, 

 But they are absent from the western shores of conti- 

 nents. California and Western Mexico have no true 

 reefs and the West Coast of Africa is also free of these 



i5 



