32 Journal of Comparative Neurology and Psychology. 



certainly erroneous, at least so far as the utterances of pigeons are 

 concerned. It may be granted that the qualities (timbres) and the 

 intensities of sounds cannot be accurately determined outside of the 

 physical laVx»rator}' ; but in this respect the qualities and intensities 

 of sounds are not very different from shades of color, feeling to the 

 fingers, and many such vague impressions which are used in so-called 

 accurate description. Those features of sounds which have to do with 

 pitch and with time, on the other hand, are as susceptible of accurate 

 description as are the forms and dimensions of visible organs. 



It must be remembered, too, that for the purpose of comparative 

 study, a description need not go minutely into every detail. This 

 study is to include a comparison of each utterance of the ring-dove 

 with other utterances of the same bird, and with corresponding utter- 

 ances of the opposite sex, of the young, and of different species. For 

 all of these comparisons it suffices to have a general knowledge of 

 each utterance as regards timbre and intensity" and an accurate 

 knowledge of each as regards pitch and time. 



For the study of expression, on the contrary, it is desirable that 

 intensity and timbre, in addition to the other two sets of characteris- 

 tics, be measured with extreme accuracy. Such a work of measure- 

 ment, for one species of pigeon alone, would involve years of labor ; 

 indeed, such work is just beginning to be done, and its methods are 

 just beginning to be developed, even for the human voice.^ Hence 

 we must be content for the present to describe the changes of ex- 

 pression in the dove's voice by means of non-quantitative musical 

 signs and popular language ; and though these means of description 

 are broad and indefinite, they are full of meaning, and may convey 

 a good idea of expression. 



There is only one point in which I have found it necessary to 

 depart in any way from the regular musical notation. That point 

 concerns the glide, or portamento. Pigeons' notes very commonly 

 glide with absolute continuity from one pitch to another. I have 

 not been able to find any convenient musical sign which indicates such 

 a glide, as distinct from a mere legato; hence, I have adopted the 



'E. W. Scripture. The Elements of Experimental Phonetics. New York, 

 19(J2, pp. xvi -h 027, PI. xxvi. 



