VESTIGIAL PARTS. 63 



part which has had important functions in an animal, 

 and then has had its function gradually abrogated by 

 another part, is more prone to be persistent in rudiment 

 than remnants of organs of less importance. Darwin 

 expresses this view of the matter thus : " Organs now 

 of trifling importance have probably been of high im- 



FiG. 31. A Horned Sheep with cervical auricles. 



portance to an early progenitor, and, after being slowly 

 perfected at a former period, have been transmitted to 

 existing species in nearly the same state, although now 

 of slight use." That mere disuse is insufficient to pro- 

 duce abolition of a part is illustrated in a striking 

 manner by the cervical auricles in goats, pig, and man. 

 These ears or auricles, in so far as we know, subserve no 



