166 
THE CONDOR 
Vol. XVI 
fancy values accordingly. For instance, out of several hundred osprey eggs 
which have passed through iny hands I have two sets in Avhich the markings 
are all purple, and 1 recently received a set of Swamp Sparrow’s eggs Avhich 
the collector aptly termed “Pooecetes-like”. Many (possibly all) species of 
Corvus occasionally lay eggs in Avhich the customary green is replaced by red, 
though such instances are exceedingly rare. In just one siiecies, as far as I am 
aware, this is the normal type and T have several sets of Corvus capensis from 
South Africa Avhich closely resemble these peculiar eggs of our raven. 
We have all run across nests Avhich obviously contained eggs produced by 
more than one female ; hoAv often and among Avhat species are such instances 
likely to occur? I do not think there is much data available, but special atten- 
tion to this point Avould doubtless bring forth much hidden information. Many 
years ago 1 became sufficiently interested in this subject to record a fcAV cases 
and, quite incidentally, coin a new word — co-nidification — which barely es- 
caped immortalization in the Century Dictionary !* 
As I have already stated, the extension of a collection beyond the safe 
limits of the A. 0. U. List is a difficult, expensive and altogether serious under- 
taking. It requires infinite time and patience to build up an exchange list, and 
for some entire regions this is quite impracticable. In Europe, the customs dif- 
fer markedly from ours, data consists customarily of date and locality only and 
as dealers handle a very large percentage of the eggs it is a heartbreaking 
business to obtain really desirable material from the original sources. In South 
Africa and South America collectors are feAv and far between and oology has 
received scant attention in most localities. Australians, on the contrary, have 
every reason to be proud of their Avork along these lines. There are many 
active field oologists Avhose specimens and data compare favorably Avith our 
A'ery best, and my personal acquaintance and extenshm correspondence AAuth 
them has been a real pleasure in every Avay. Of Indian oologists I knoAv little 
and my collection is as yet practically barren in this rich field despite strenu- 
ous efforts at cultivation for several years. But in spite of the draAA^backs, I 
must confess that the collector AAdio once takes the plunge and becomes aAvake 
to the possibilities of exotic material is not likely to give up for lack of interest. 
Thus, it is particularly fascinating if one is looking at oology from the 
comparatiA'e point of aucav, to fill the gaps Avhich occur in most of our native 
groups. There are feAV families or even genera Avhich are strictly North Amer- 
ican and it is surprising to find Avhat of the novel types fit in among our OAvn 
familiar species. The folloAving examples, AAdiich might be extended indefinite- 
ly, may serve to illustrate this point. The plain, light blue eggs of our oAvn 
bluebirds (Sialia) form an interesting series, but the real home of their allies, 
the chats {Saxicolinae) , is in the Palearctic region and eggs of the many spe- 
cies found there present an ‘endless variety, most of the specimens being more 
or less spotted. Again, in looking over our cabinets AA^e may observe betAveen 
the true thrushes and the Avheatears one or more sets of small, dark eggs AAdiich 
seem strangely isolated and out of place ; for North America Ave haAm only one 
representative {CyanecuJa) of the large and interesting sub-family (Enticil- 
linae) AAdiich includes not only the nightingales but also the real robins and 
redstarts after Avhich our birds Avere long ago misnamed. Many of these eggs 
are particularly beautiful and among the various species there is great diver- 
*The late Professor Coues was then at work on the zoological section; having heard 
of the word he asked for the original reference — the old O. Sz O., I think — but I inad- 
vertently neglected to inform him. 
