SKIMMING THE SURFACE 



produced into a ''beak", as in the dolphin's case. Dol- 

 phins are found in abundance in all seas, while some 

 species are inhabitants of large rivers, such as the 

 Amazon. 



The food of these animals is chiefly fish, and the 

 dolphin's long and narrow ''beak" is admirably adapted 

 for this purpose as a weapon of offence. The muscular 

 power of the dolphin is enormous. It has been calculated 

 from its resistance to a towing-line that its muscles are 

 capable of generating energy at least seven times greater 

 than the muscles of other mammals. 



The common dolphin usually measures from six to 

 eight feet in length, tapering from the centre (where its 

 dorsal fin rises to a height of about ten inches) to both 

 extremities. The "beak" is about six inches long, and the 

 mouth is armed with sharp, curved teeth — about forty 

 or fifty on each side of its jaw. The ear aperture is ex- 

 tremely small, the eyes are of moderate size, and the 

 "blow-hole" through which the creature breathes is 

 crescent-shaped. 



Dolphins occur in all seas, and feed mainly on fish, 

 but they will eat lower creatures such as molluscs and 

 crustaceans. They are greedy eaters and will on occasion 

 consume cuttle-fish. The mother dolphin bears one baby 

 (or very rarely, two) at a time, and she watches over her 

 infant, or infants, with extraordinary care, even when 

 they have grown to a considerable size. Her milk is rich 

 and abundant, and she suckles her progeny with all the 

 tenderness of a human mother, floating in a slightly side- 

 long position while doing so. 



Calculated from the known speed of vessels, dolphins 

 and porpoises travel at anything up to thirty-seven miles 

 an hour. Dolphins, being the speedier of the two, may 

 even exceed this speed on rare occasions. Dolphins have 

 been watched by the crews of destroyers, doing over thirty 

 knots — zigzagging from side to side in front of the vessels. 



Dolphins and porpoises exhibit such amazing agility 



53 



