GARDEN WARBLER 



larly ; we observe an active response on one occasion and are 

 surprised to find an absence of response on another ; there is 

 no uniformity of behaviour in this respect. When the motor 

 reactions are excessive and much suffused with feeling tone, 

 we rarely find occasions when the usual stimulus will not 

 produce the customary active response, but when the 

 emotional behaviour as a whole does not occupy so high 

 a level of development such occasions are by no means 

 uncommon, and it is therefore not always easy to decide as 

 to the extent of the variation between one individual and 

 another. 



The young are hatched in about twelve days and remain 

 in the nest from nine to ten days. They are naked at birth 

 and have their eyelids sealed. The colour of the inside of 

 the mouth is pink, and two dark-coloured spots are con- 

 spicuous at the base of the tongue. On the third day their 

 eyes are open and the primaries are then just appearing, 

 and on the fourth day the feathers on the back appear, the 

 primaries being J" in length. Between the fourth and fifth 

 days considerable advance is made in their growth and 

 the quills can be seen on all the feather tracts. On the 

 sixth day feathers appear on the breast and flanks, and 

 between the sixth and seventh days another considerable 

 change is noticeable, as all the feathers begin to show colour. 

 During the remaining two days or so growth continues 

 rapidly, but nevertheless they finally leave the nest in what 

 seems to be a very undeveloped state considering the dangers 

 that threaten them. The thick tangled undergrowth, in 

 which they so successfully conceal themselves, secures them 

 no doubt from certain enemies, though at the same time 

 increasing the risk from others. The smaller rodents which 

 abound in such places must make havoc amongst such help- 

 less victims. At this stage the young sit singly or together 

 on the smaller branches of some thick bush and utter periodi- 

 cally a faint note which is difficult enough to hear but still 

 more difficult to locate. This note acts as a guide to the 



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