THE HISTORY OF WHALES— THEIR ADAPTATION TO 

 LIFE IN THE WATER 



By REMINGTON KELLOGG 



Bureau of Biological Survey, United States Department of Agriculture 



CETACEANS are air-breathing 

 warm-blooded mammals, gen- 

 erally having pointed heads, 

 torpedo-shaped bodies, fin-like 

 fore limbs, and horizontal caudal flukes. 

 All external structures and protruding 

 organs which might offer resistance to the 

 water have been either eliminated or sunk 

 below the surface level. This group em- 

 braces the extinct zeuglodonts (Archaeo- 

 ceti), the whalebone whales (Mysticeti), 

 and the toothed whales (Odontoceti), 

 including porpoises, dolphins, beaked 

 whales, and sperm whales. 



Naturalists and sea-faring people have 

 been recording their observations on 

 whales for many centuries and, although 

 early literature dealing with the group 

 contains much that is fanciful and little 

 that is real, it is evident that whales and 

 porpoises have long been objects of interest 

 to mankind. The existing cetaceans are 

 so well adapted for a continuous life in the 

 water that naturalists of the Middle Ages 

 believed that they must belong to the fish 

 tribe. John Ray (1671) was one of the 

 first to discover that the relationships of 

 the cetaceans were with land mammals 

 rather than with the fishes. Subsequently 

 these animals attracted the interest of 

 other naturalists, many of whom pub- 

 lished their observations, so that the 

 literature relating to cetaceans now com- 

 prises several thousand titles. Study of 

 the anatomy of living whales and the 



bones of extinct species has led to many 

 interesting speculations. 



Why the progenitors of the whales for- 

 sook the land is a tempting field for specu- 

 lation, but while we do know that some 

 archaic land mammals were induced to 

 take to water, the reasons for this action 

 do not admit of direct proof. It is possi- 

 ble that the forebears of the whales may 

 have thus found either a safe refuge from 

 more active predatory types, or an abun- 

 dance of food in shallow water and along 

 the shores, and available data indicate 

 that the late Sir William Flower (1883) 

 was not far wrong when he suggested that 

 the ancestors of whales frequented fresh 

 water and that search for their remains 

 should be made in the fresh water de- 

 posits of the Cretaceous period. Many 

 anatomical and physiological adjustments 

 were necessitated as these mammals be- 

 came better adapted to their aquatic 

 surroundings, and those which became 

 perfectly adapted to this sort of habitat 

 had to undergo a number of fundamental 

 structural alterations to cope with the 

 new conditions. Some of the modifica- 

 tions which were tried out in the course of 

 geological time proved more successful 

 than others, and as a result we find that 

 old species continuously disappeared and 

 new ones took their places. In conse- 

 quence of the substitution of certain parts 

 and the complete elimination of others, 

 it is not surprising that living repre- 



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