110 THE LIFE OF A BIRD. 



formed by the long- tailed titmouse, and so artfully 

 placed on the branch of an elm, and so closely 

 resembling the knot of a tree in external appear- 

 ance, that it was extremely difficult of detection. 

 This nest had a feather fixed so as to overhang 

 the entrance, forming a sort of valve, which was 

 pushed in or out as the birds left the nest or came 

 into it. Mr. Jesse considered it to have been placed 

 there in order to act as a little door, and so to 

 preserve the warmth of the nest, particularly as it 

 happened to be extremely cold weather at the 

 time the birds were laying their eggs. A corre- 

 spondent of the Zoologist has remarked the same 

 interesting fact. The nest seemed to be but just 

 finished, and w*as empty. It was of an oval shape. 

 There was a long entrance to the nest proper, 

 which was slightly arched, so that the interior of 

 the domicile was thus protected from wind and 

 rain. But there was a still more curious contriv- 

 ance, by which the nest was guarded from the 

 intrusion of unwelcome visitors. A strong feather 

 was fastened to the nest by hairs woven around 

 it and through the moss and lichens. It was so 

 placed, that its top hung over the hole. It bent 

 upwards with the slightest pressure, and imme- 



