W. H. THORPE 



83 



/. n 



m\ 



Fic;. I 

 'Normal' song of British chaffinch {Friiii;illa coclchs (.'t'/zsj/rn') Vertical 

 scale: frequency in kc./s. Horizontal scale: time m seconds (Similarly 

 Figs. 2-1 1). 



'i k '1 I 



WWWs 



10 15 2 2-5 



^^WM'^iw««\iWrti\ 



05 



l-O 15 20 2 5 



MhVVVUsv 



Figs. 2-4 

 Song of three hand-reared isolates. GW, lune 24th, 1954; B/BkY, 

 May 25th, 1957; and BkW/W, June 24th, 1955. 



