•\varbll:r st)N(;s. i.-) 



make it difficult to identify to any but the one who is hearing 

 it for the first time. Another variation often indulged in by 

 some of the more versatile singers is the substitution of one 

 vowel sound for another. When this is accompanied with the 

 variations noted above there may be some difficulty at first, 

 but v\'hen the style of utterance is once learned variations are 

 not deceptive, but rather pleasing for their variety. Each 

 species has a style all his own which can be relied upon in any 

 given localit3^ however variable his song may be. 



There seems good evidence that there is also a .seasonal 

 variation, or a migratory variation. Some birds sing one style 

 of song when they start from their winter homes for the 

 north, another during the latter part of their journey, and 

 still another when they are well settled for the sunnner. How 

 universal this is I am unable to say. With some species the 

 difference between the songs is decided, in others nuicli less so. 

 It would be interesting to know whether nesting birds of one 

 species sing the same in all localities where they nest, or 

 w'hether there is variation of much consequence. My own 

 notes .show only that with the few species which nest in 

 lyorain county, Ohio, the .songs of the birds which remain are 

 somewhat different from the songs of those that pa.ss further 

 north. Do the Ontario nesting birds .sing like tlie Ohio nest- 

 ing ones? Probably. 



Is there a longitudinal variation as well as a latitudinal 

 one ? If any probably far less marked. With .some other 

 species, notably the Dickcissel, there is a marked difference 

 betw^een the singing of the Iowa and the northern Ohio birds. 

 If there is such a difference among the Warblers the notes at 

 hand give no evidence of it. We might naturalh' look for 

 .some variability in the .sub-species, growing into recognizable 

 permanent differences, .since they are variations in other 

 respects from the .species. But w^e might argue from this that 

 since genera are assemblages of .species which in .some prehis- 

 toric time evolved from a common stock by differentiation, that 

 therefore the .songs of all the members of a genus .should bear 

 a clo.ser resemblance to each other than to tho.se of any other 

 genus. Either this is not true, as we shall .'^ee, or else the 

 present sy.stem of classification is wholly wrong ; an unlikely 

 suppo.sition. Often .species of widely separated genera re.sem- 



