Sept., 1922 THE MIMETIC ASPECT OF THE MOCKER’S SONG 157 
eapacity for running and jumping of a very creditable sort, yet a pacemaker 
is necessary to develop a winning athlete in an Olympic track meet. In sum- 
ming up, then, no claim is made that the perfection of a mocker’s so-called 
‘‘imitation’’ is attained without examples to copy—without oral assistance— 
but the suggestion 1s made that the basic phrases of a mockingbird’s vocabu- 
Fig, 38. NEST OF THE WESTERN MOCKER, IN TUNIS CACTUS. 
lary which simulate the notes of other birds may well be as intrinsic a part of 
his transmitted vocal ability as are those other interludes which have no ana- 
logies among other species. 
Pasadena, California, June 7, 1922. 
