July, 1914 
A PLEA FOR COMPARATIVE OOLOGY 
167 
sity, from delicate pinks and blues to dark olive-browns. Among the Turdinae 
we find that eggs of the twenty or more North American forms all have as 
ground color some shade of green or blue, but this is not common to all the true 
thrushes ; in T. viscivorus it varies greatly from gray or greenisli gray to red- 
dish-brown ; eggs of M. olivacea from South Africa are similar while in one 
siiecies only {Oreocichla mollissima) it is white. 
Doubtless most of the facts and speculations set forth above are familiar 
to readers of The Condor and, having little claim to originality, my only excuse 
in presenting them is an earnest belief that the time has come in this country 
when the study of egg collections as a whole should receive more attention and, 
particularly, that our collections should be so built up and expanded as to guar- 
antee the most fruitful results. 
V. S. 8. Washington, Puerto Plata, Santo Domingo, May 20, 1914. 
