10 BRITISH BIRDS. 



pygostyle, the nestling lying on its belly ; (ii.) along arm 

 of wing, a separate measurement for each segment of 

 the limb ; (iii.) ditto for foot measurements ; (d) colour 

 of the markings of the inside of the mouth, and relative 

 sensitiveness of its various parts to stimulation by food ; 

 (e) wing-claws, how long retained ? (/) " heel-pads," 

 when prefeent, and observations as to their use ; (g) dis- 

 tribution of down where present when first hatched ; 

 whether two down-plumages are developed ; date and 

 process of development of down after hatching ; dates 

 of shedding of down, and sprouting of quills ; process 

 and dates of development of quills. 



10. Feeding of Nestlings. — Share of each parent 

 in the feeding. Visits per hour. Time of day when feeding 

 visits are most frequent. Distribution of the food among 

 the young. Do any receive more than their share and 

 why ? Description of the act of feeding. Nature of the 

 food given at each stage. Is it regurgitated by the parent ? 

 If so, to what extent is it digested ? (To find this, insert 

 a quill into the throat of the nestling immediately after 

 it has been fed, and examine under a lens the matter 

 adhering to the quill. Failing this method, the nestling 

 may be made to regurgitate by pressure or tickling. ) How 

 long are the nestlings fed on regurgitated, how long on 

 fresh, food ? Do the cock and hen birds bring different 

 food to the nest ? 



Experiment. — Place a nestling (at various stages of 

 growth) in a conspicuous place at the foot of the nest or 

 near it, and note if the parents feed it or take any notice 

 of it. 



11. Cleaning the Nest. — Methods adopted at various 

 stages of the nestling's growth. When the faeces are 

 removed by the parents, note whether they are eaten, or 

 merely carried away and dropped. If the latter, at 

 what distance from the nest. 



12. Protection of Nestlings (a) by coloration or 

 behaviour, whether of the nestlings or the parents ; (6) 

 by the situation of the nest or nesting-place. 



