THE OOLOGIST 



51 



data; though he regards the facts 

 herein set forth as tenative and sug- 

 gestive rather than positively conclu- 

 sive. He has to thank C. W. Crandall, 

 Thomas H. Jackson, Robert P. Shaip- 

 les, J. Clair Wood and others for data 

 contributed. 



The Bald Eagle is at present recog- 

 nized in two sub-species; Haliaeetus 

 leucocephalus lencocephalus and H. 

 leucocephalus alascanus. 



The Canadian border is the present 

 dividing line between the breeding 

 ranges of the two. As far as the know- 

 ledge of the writer goes, the division 

 of the species is based on size alone, 

 there being no other recognized differ- 

 ences. 



Since this is so, it seems reasonable 

 that the line of division should be 

 along the range of the average sized 

 birds and not a mere political or na- 

 tional boundary, unless indeed the two 

 should be found to be identical. 



Several series of skins examined, 

 from Maine and from Florida, show 

 enormous differences, the Maine birds 

 corresponding very much closer to 

 Alaskan and Canadian birds than to 

 those from Florida. . This of course 

 would be conclusive evidence, if they 

 were breeding birds, but very few 

 New England breeding birds are avail- 

 able in collections. Further more it 

 would require long and arduous en- 

 deavor to secure a series of the birds, 

 to say nothing of the sentimental side; 

 for it would be a pity to sacrifice so 

 many of this species that is becoming 

 none too common. 



The writer does not claim that anj^- 

 thing conclusive can be drawn from 

 the measurements of one egg or one 

 set of eggs, but does maintain that 

 averages of series of eggs of this size 

 do give very conclusive evidence. 



The following averages have been 

 obtained: 



Locality. No. of Eggs. Meas. in ins. 



Canada 



7 



2.95x2.30 



Maine 



7 



3.01x2.21 



Michigan 



3 



2.89x2.20 



Oregon 



6 



2.90x2.22 



Del. Mr. & Va. 



19 



2.81x2.20 



Fla. & Tex. 



65 



2.79x2.14 



Average of these averages 2.89 x 2.21 



The longest egg is one of a set of 

 two, collected by the writer in Lincoln 

 County, Maine, and now in his col- 

 lection, the rest measuring: 3.20 x 

 2.27, 3.04 x 2.21. 



The egg showing the largest meas- 

 urement of the shorter diameter is 

 one of a set of two collected in Alaska 

 and now in the collection of C. W. 

 Crandall, the set measuring: 2.95 x 

 2.37, 2.88 X 2.35. 



The smallest eggs are found in Flor- 

 ida sets, which measure: 2.46 x 2.00, 

 2.52 X 2.01, and 2.51 x 1.94, 2.51 x 2.00. 



From the foregoing figures it may 

 be seen, that the Oregon and Michigan 

 eggs correspond very closely with the 

 general average; the eggs from Flor- 

 ida and Texas are very much smaller; 

 those from Delaware, Maryland and 

 Virginia somewhat smaller; while 

 those from Maine and Canada and 

 Alaska are distinctly larger than the 

 average. 



In addition to this evidence, Nature 

 seems to have developed the dividing 

 line between these sub-species in 

 Eastern North America. If there are 

 any instances of Bald Eagles breed- 

 ing at present in Massachusetts, 

 Rhode Island, Connecticut, or in fact 

 along the Coast between Maine and 

 New Jersey; the cases could hardly 

 be called other than spordic. 



This break in the breeding range of 

 the species is, to the writer's thinking, 

 the natural and scientifically true 

 boundary between the sub-species. Or 

 to be more specific, it would seem 

 logical to establish the boundary be- 



