NOTES. 221 



this position, these birds passed in twos and threes. They 

 were flying about six to ten feet above water in a most 

 businesslike way, and did not seem at all lost, in fact none 

 settled on board and only one circled round the ship for a few 

 minutes until, being joined by two others, all three went 

 straight away due N. by E. out of sight. The weather at the 

 time was dead calm, hot, and cloudless. As near as I could 

 reckon we were 190 miles equidistant from Malta and the 

 nearest point on the African coast. I may also mention 

 that a Blue-headed Wagtail (M. flava flava) which came 

 aboard when in this position was still on board when ve 

 sighted Alexandria ! C. B. Ticehurst. 



THE MEANING OF BIRDS' SONGS.* 



The reptiles of to-day have little or no voice, and it is probable 

 that the particular reptiles that were the ancestors of birds 

 were almost voiceless. But as soon as the power of flight 

 was developed and long journeys became possible, some 

 special means of bringing the sexes together must have been 

 an urgent need, especially in the case of birds that haunt 

 woods and thickets. 



It seems to me, therefore, that we must hold that the 

 call-note was the germ of the song, in fact that a bird's song 

 is a glorified call-note, a call-note that has been elaborated 

 for sexual purposes, so as to be of service not only for 

 attracting the attention of one of the other sex, but for 

 exciting sexual emotion. That many birds sing in winter 

 when they have no thought of nesting is no objection to 

 this view, for when an organ has once been developed to 

 meet a definite need, the animal that owns this organ 

 may take a pleasure in its exercise even when there is 

 nothing to be gained by it. The power of flight is a 

 sine qua, non, not a mere luxury to most birds : but many of 

 them, e.g., Gulls, perform gyrations in the air for pleasure 

 pure and simple, so strongly do they feel the " mere joy of 

 living." In the same w r ay mere superabundance of vitality 

 drives a boy or man to play football, but the combative- 

 ness and the love of play, for which football is an outlet, 

 are essential to a virile race. -p. W. Headley. 



It is perhaps not generally known that when a Skylark is 

 being closely pressed by a Merlin it will frequently — indeed, 

 almost always — utter a low, twittering song. This is especially 



* Dr. P. R. Lowe writes that in his note on page 183, line 14 from 

 bottom, " or nestling stage " should read " or resting stage." 



