THE SEMI-ANNUAL. 19 



down a storm of dissent by insisting that the Wood Thrush in 

 Iowa, at least central Iowa, never use mud in making their nests. 

 Brewer, Baird, Coues, Ridgway, Davie and all the rest find 

 Wood Thrushes which use mud, but I cannot. They must dis- 

 sent with my birds, not with me. The question arises, " is this 

 difference local or is it a western characteristic ?" There seems 

 to be no logical reason why the Wood Thrush in Iowa should 

 use punk and not mud, when its eastern brothers and sisters use 

 onlv mud. Here is a nut for our workers to crack. 



DIMENSIONS AND WEIGHT OF NEST. 





DIAM 





DEPTH 









Outside. 



Inside. 



Outside. 



Inside. 



"Weight. 



Berwyn, Pa. 



4.00 

 to 



2-75 

 to 



2.50 

 to 



1-75 

 to 



2.00 

 to 





4-50 



3-25 



3-50 



2.25 



5.00 oz 



Columbia, Pa. 



3-50 



2-75 



4.00 



2.50 



/zlh 



Wauwatosa, Wis. 



5.00 



3-50 



3.00 



2.50 





Grinnell, Iowa. 



4.00 

 to 



2-75 

 to 



2.50 

 to 



1-75 

 to 







4-75 



3-25 



•3-75 



2.15 





The vai-iation in size is small compared to either of the fore- 

 going species ; the nest is much more compactly made. 



DATE OF KESTINU. ARRIVAL. 



Last. Average. Time Building. First. Common 



6-10 ^.n 





First. 



Last. 



Berwyn, Pa. 



.■;-25 



7-9 



Columbia, Pa. 



s-27 



7-10 



Pittsburgh, Pa. 



5- 1 1 



6-17 



Perrineville, N. J. 



5-10 



7-1 



Grinnell, Iowa. 



5-22 



7-17 



<')-7 days 

 f>-i 10 days 



4r, 4.25 



5-1 5-IO 



