94 THE INFANCY OF ANIMALS 



motives, since a sprig of holly with berries on has been 

 found in the nest of the golden eagle. 



The eagle and the osprey, and their kin, afford the 

 necessary shade for their panting offspring by standing 

 over them with outstretched wings, and a similar plan is 

 adopted to shield them from rain, so fatal to young birds 

 that even ducks adopt the same device. 



So far nothing has been said of disease in its relation 

 to nestling and young birds. As a matter of fact there 

 is little to be said, for the matter has never formed the 

 subject of scientific inquiry. But so far as the evidence 

 goes disease plays a very unimportant part in the death- 

 rate of young birds. There are, however, exceptions to 

 every rule : and records of an " enormous " mortality 

 in colonies of the black-headed gull have been made 

 more than once, during recent years, though no effort 

 seems to have been made to ascertain what particular 

 form of disease was the cause of this. Coccidiosus and 

 " gapes " are probably the most common cause of out- 

 breaks of this kind. Records of a mysterious disease 

 affecting the feet of young terns, causing the toes to 

 slough off, have been made from time to time, but the 

 mortality from this source appears to be of a negligible 

 quantity. 



One turns with a sense of satisfaction from the con- 

 templation of the ravages of death by violence, and death 

 by disease, to the subject of play among nesthng birds, 

 though unhappily on this theme our ignorance at present 

 is immense. The information that is to be gleaned from 

 published records is of the scantiest. Such as it is, however, 

 it is the more valuable because it affords us an insight into 

 the play of birds of widely different kinds. 



Mr. Macpherson's wonderful monograph on the golden 



