20 THE SEMI-ANNUAL. 



EGG3 IN SET. MEASUREMENTS. 



Largest. Smallest. Av. Largest. Smallest. Average. 



Berwjn, Pa. 4 i 3 i.iix.77 .95X.67 i.oix.74 



Pittsburgh, Pa. 4 2 3 1.02X.76 

 Wauwatosa, Wis. 524 



Grinnell, Iowa. 423 i.iix.75 .96X.72 i.oix.74 



Perrineville, N. J. i.oox.'j^ 



In the average measurements we very closely agree, much 

 more so than, the professionals whose records are as follows: 

 i.oo to 1.1OX.70 ; .95X.65 ; 1.04X.73; 1.00X.75; 1.03X.74; 1.08 

 X.70. They show a very great diversity in form as well as size. 

 One author — ,95x.65 — gives the average even smaller than the 

 smallest in the table above. In their reckoning compare the long 

 egg — 1.10X.70 — with the shortest — i.oox.75 — and then ask how 

 can authors differ so widely in average measurements. In form, 

 eggs are very diversified ; from short ovate they run through 

 ovate pyriform, ovate, elliptical ovate to elongate ovate. 



COLORATION. 



Mr. Burns describes the eggs as " greenish-blue with very 

 little variation ;" one in a set of three is light blue. Mr. Ely 

 says : " they are of a uniform deep blue." Mr. Jacobs describes 

 them as " a very light blue with greenish tinge." I have des- 

 cribed a large number of eggs as " a uniform light nile-blue." 

 Fully half of the Iowa eggs have a limy deposit when fresh. 



PERIOD OF INCUBATION. 



At Berwyn, Pa. and Grinnell, Iowa the bird lays each day 

 and is fourteen days setting. In fair weather, the young leave 

 the nest in about ten days, sometimes not for fourteen. 



Were our report not I'estricted to the department of Oology, 

 and should we not infringe upon the rights of the Melological 

 Committee, we would be delighted to pause here to speak in 

 words ol highest praise of Wood Thrush's song. Of all the 

 birds in the deep forest-land, he has no peer. His song is suited 



