MAMMALS 189 



Of late years the civilised nations engaged in Whale- 

 hunting have collaborated to make some kind of investi- 

 gations into Whale movements and economy. The 

 migrations of Whales are largely traced by means of small 

 silver harpoons inscribed with a duly indexed check- 

 number, and these harmless weapons are shot into the 

 animal's blubber, so that when at last killed or washed 

 ashore some idea of its travels may be arrived at through 

 their " passports." 



Contrary to the general rule that the larger the animal the 

 more slowly does its progeny develop, Whales would appear 

 to be sexually mature at the very early age of z\ years. 

 The young are suckled in typical mammalian fashion, and 

 it has been ascertained that the single progeny may be 

 relatively huge, that of an 80 ft. Blue Whale being over 

 20 ft. at birth. In view of their early maturity it is unlikely 

 that Whales live to a great age. 



Whilst a number of species of Whales are evidentiy 

 confined to certain areas, a large percentage are more 

 or less cosmopolitan, touring the seas according to the 

 dictates of prevailing currents, and the distribution of their 

 food supply. It thus happens that Whales often make very 

 unexpected appearances and our own shores have more 

 than once seen the arrival — in bulk — of various kinds that 

 had previously been recorded as more or less restricted 

 to far distant areas. As an example, the False Killer 

 (Pseudorca) had up to the year 1909 been known chiefly 

 from chance examples found in such widely separated 

 seas as those of Denmark and Tasmania. Yet in 1929, 

 120 of these Whales were stranded in Dornoch JFirth, 

 Ross-shire, none being seen again until a score of 



