238 THE ZOOLOGIST. 



(e.g. Mallard, Crow, Tree Creeper) would address his mate in 

 that one note, and, under the influence of sexual ardour, would 

 repeat that note many times in succession. The number of 

 repetitions uttered at one time would probably depend upon the 

 amount of breath expended in uttering each note ; thus, if an 

 inspiration were taken for each note, the utterance might be 

 extended, as it is in the case of the Grasshopper Warbler,* but 

 if one breath were employed for several cries the number of these 

 could not be great. Such repetitions would be frequently uttered 

 in the same successive intervals of pitch, in the same way as the 

 cries of our railway porters and street hawkers are gradually 

 regulated to unvarying repetitions. 



It may be asked why, if this occurs, do we hear so many 

 birds, like the Crow and Duck, which, having limited voices, 

 utter no defined phrase ? The answer is that their general 

 mode of life, or the brevity of their courtship, has been 

 unfavourable to vocal development. It is certain that the 

 young of many song-birds (e. g. Lark, Chaffinch, Yellow Bunting, 

 Cirl Bunting, and Greenfinch) develop their first songs and 

 phrases from mere repetitions of their call-notes, as may be 

 observed in autumn or early spring ; and the suggestion that the 

 remote progenitors of these birds acquired during the lapse of 

 generations what their descendants can gain in a month, is sup- 

 ported by physiological analogies. The most familiar instance 

 of the construction of a phrase by means of repetitions is found 

 in the common barn-door cock, which, when first attempting to 

 " crow," utters merely an ordinary alarm-cry (which is also the 

 "crow" of the broody hen), and repeats this several times in 

 rapid succession. Improving with practice, he is soon able to 

 blend the notes together, and form the complete " crow." 



We now arrive at the consideration of restricted bird-song, 

 which consists of vocal sounds, neither call-notes nor danger- 

 cries, uttered by birds. The first songs seem to have been, as 

 above suggested, arbitrary phrases composed of repetitions of 

 call-notes. The songs of the Nuthatch, Green Woodpecker, 

 Tree Creeper, Bullfinch, and Cirl Bunting (and Ortolan Bunting, 

 so far as I have heard in two individuals), are nothing more than 



'- ;: Many extended bird-phrases seem to be accompanied by a rapid move 

 mei it of the lungs similar to that which occurs during human laughter. 





