186 TERRITORY AND REPRODUCTION 



ture reached 58 F. the bodies of the young 

 retained their warmth, and that under such 

 conditions even a night's exposure had little, if 

 any, effect ; so that even supposing that the 

 parents were absent during the night, the death 

 of the young cannot be said to have been due to 

 a failure of the parental instinct, because under 

 normal conditions and under such has their 

 instinctive routine been evolved their absence 

 would not have prejudiced the existence of the 

 offspring. I attribute the collapse of the young 

 solely to the exceptional cold that prevailed at 

 just the most critical time, and I base this 

 conclusion partly on the experience gained from 

 experiment, but mainly on their condition 

 observed at different intervals ; for during 

 exposure they collapsed rapidly, their flesh 

 became cold and their movements sluggish, 

 their response grew weak, and gradually they 

 became more and more feeble until they could 

 scarcely close their bills after the mandibles had 

 been forced asunder. Yet, even after having 

 reached so acute a stage of collapse, the warmth 

 from the body of the brooding bird was 

 sufficient to restore them temporarily ; once 

 more they would become lively and responsive, 

 only, however, to revert to the previous condi- 

 tion soon after the parent had again abandoned 

 them. Doubtless their power of resistance 

 grew less and less during each successive period 

 of exposure. 



If the nestling Bunting is to be freed from 

 the risk of exposure, it is evident that there 



