igo THE BIOLOGY OF THE SEASONS 



would be interesting to discover whether there is in the 

 normal environment of the gullery some alarming sound 

 corresponding to the low whistle, for that and a hiss were 

 the only sounds (apart from their neighbours' cheeping) 

 that seemed to fix their attention and induce cowering. 

 Later on the birds learned to associate certain sounds 

 with their food supply. 



The sensitiveness to cold, which unfortunately led to 

 a repeated reduction in the number of young birds, was still 

 very marked on the second day. Even on a rug in front 

 of the fire they would creep into the observer's hands or 

 crawl up his sleeve, apparently for warmth. At the pond 

 many of the young birds seemed to be in a state comparable 

 to cold coma, and it may be suggested that some measure 

 of this may be useful in tending to prevent premature 

 excursions which would in many cases inevitably land 

 the birds in the water. 



As is well known, the adults are very combative birds, 

 and it was interesting to observe a fight early on the second 

 day of life. The child is father of the man. Beth pecked 

 at Aleph's bill, and Aleph responded, beginning a tussle so 

 forcible that separation seemed advisable. It was striking 

 in connection with these youthful tussles to notice the 

 interlocking of the bills, just as may be observed in the 

 combats of the adults. As has been pointed out by Bor- 

 dage, these bill-wrestlings are of biological interest in con- 

 nection with the regenerative capacity shown by injured 

 beaks in various kinds of birds, such as storks. At this 

 high level in the animal series it is rare to find much re- 

 generative capacity, and its retention in the case of birds' 

 beaks may be in part interpreted in the light of the fact 

 that injuries to the beaks are frequent in natural conditions. 

 For Lessona's famous law of the distribution of regenerative 

 capacity is that it tends to occur in those animals and in 



