166 THE CONDOR Vol. XVI fancy values accordingly. For instance, out of several hundred osprey eggs which have passed through my hands I have two sets in which the markings are all purple, and I recently received a set of Swamp Sparrow's eggs which the collector aptly termed "Pooecetes-like". Many (possibly all) species of Corvus occasionally lay eggs in wkich the Customary green is replaced by red, though such instances are exceedingly rare. In just one species, as far as I am aware, this is the normal type and ?[ have several sets of Corvus capensis from South Africa which closely resemble' these peculiar eggs of our raven. We have all run across nests Which obviously contained eggs produced by more than one female; how often and among what species are such instances likely to occur ? I do not think tliqre is much data available, but special atten- tion to this point would doubtless ?ing forth much hidden information. Many years ago I became sufficiently interested in this subject to record a few 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. O. 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 few and far betv?een and oology has received scant attention in most localities. Australians, on the contrary, have every reason to be proud of their work along these lines. There are many active field oologists whose specimens and data compare favorably with our very best, and my personal acquaintance and extensive correspondencs with them has been a real pleasure in every way. Of Indian oologists ! know 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 drawbacks, must confess that the collector who once takes the plunge and becomes awake to the possibilities of exotic material is not likely to give up for lack of interest. Thus, it is particularly fascinating if on? is looking at oology from the comparative point of view, to fill the gaps which Occur in most of our native groups. There are few families or even genera which are strictly North Amer- ican and it is surprising to find what of the novel types fit in among our own familiar species. The following examples, which might be extended indefinite- ly, may serve to illustrate this point. The plain, light blue eggs of our own bluebirds (S?alia) form an interesting series, but thee real home of their allies, the'chats (Saxgcol?nae), 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 le ss spotted. Again, in looking over our cabinets we may observe between the true thrushes and the wheatears one or more sets of small, dark eggs which seem strangely isolated and out of place; for North America we have only one representative (Cyanecula) of the large and interesting sub-family (Ruticil- linae) which includes not only the nightingales but also the tea! robins and redstarts after which our birds were 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. &- O., I think--but I inad- vertently neglected to inform him.
