626 CYPSELUS MURARIUS. 



scales of the Scotch Fir, together with some resinous matter 

 in one of these nests. 



In another nest sent to me by ISIr Weir, the external parts 

 are similarly constructed, the feathers in the interior are agglu- 

 tinated in the same manner, and there are numerous bud- 

 scales of the fir, to which a little resinous matter adheres. 

 But I am convinced that the principal part of the agglutinat- 

 ing substance does not consist of resin, but of gelatinous mat- 

 ter, which may probably enough be derived from the salivary 

 glands, Plate XXII, Fig. 5, II, which are aggregated crypts, 

 secreting a fluid similar to that of the proventricular glands. 



Young. — The young are of a dusky colour, at first blind, 

 and almost naked, having merely a few straggling tufts of 

 down. When fully fledged, they are of the same colour as 

 the adults, but of a lighter tint, with the edges of the feathers 

 of the head paler. They do not moult previous to their de- 

 parture. 



Fm. 272. 



