8o THE NESTS AND EGGS OF BRITISH BIRDS. 



for ingress. The amount of clay varies a good deal accord- 

 ing to circumstances : if the cavity is large the entrance 

 is reduced to just sufficient for the passage of the birds. 

 As many as eleven pounds of clay have been exception- 

 ally found attached to a nest in the side of a haystack.^ 

 Beyond this more or less elaborate structure of clay the 

 nest of the Nuthatch is crude and simple, and so loosely 

 fabricated as to render its removal entire an impossibility. 

 It is almost invariably composed of a layer of dry leaves 

 and flakes of bark, arranged at the bottom of the hole. 

 Dry grass is used, but only very exceptionally. It should 

 also be remarked that the Nuthatch sometimes enlarges 

 a hole, and then a good deal of wood-dust and chips are 

 mixed with the usual materials. The depth of the holes 

 varies considerably, from a few inches to a foot, or even 

 more. The Nuthatch is not easily driven away from its 

 nesting-hole, and will replace the clay at the entrance 

 after it has been removed repeatedly, and return }'car 

 after year in spite of regular disturbance. It will also 

 continue laying egg after egg after they are taken. The 

 Nuthatch sits very closely, usually allowing itself to be 

 removed by the hand from the nest-hole rather than 

 desert its eggs. 



Range of egg colouration and measurement : 

 The eggs of the Nuthatch are from five to eight in 

 number. They are pure white in ground colour, spotted, 

 and more rarely blotched with reddish-brown, and with 

 similar but fewer underlying markings of violet-gray. 

 The distribution of the spots varies considerably. On 

 some eggs they are uniformly distributed over the entire 

 surface ; on others they form an irregular zone or a 

 circular patch on the larger end ; more exceptionally 

 they are handsomely blotched, and even more rarely 



^ This nest is now in the Natural History Museum at South 

 Kensington. 



