§4 Shufeldt, Fossil Birds' Eggs. [ 



Emu 

 2nd Oct. 



eggs " of this class of vertebrates to be discovered are those which 

 were laid by such water-birds as breed on the ground, or in 

 swamps, or along the shores of all manner of streams and rivers, 

 or in burrows or holes in the banks of the latter, and so on. Less 

 likely specimens would be those eggs of birds of all kinds that 

 breed in nests in trees, shrubs, and hollows of all kinds in the 

 former, or those of small birds which lay correspondingly small, 

 and consequently very fragile eggs. Finally, as we know, there 

 are thousands of birds which breed on the precipitous rocks of 

 certain coast-lines in northern and southern sub-polar regions, or 

 upon lofty, rocky islands in those regions, or in similar situations. 

 There would be no chance whatever of such eggs, or rather their 

 shells, being preserved through the process of fossilization, as 

 there would be no constituents present to fill their interiors, even 

 were any of them so favourably fractured that their interiors 

 could become filled with fossilizable material. Such eggs could 

 only be so preserved through their being transported, in some way, 

 to places where they would be placed under circumstances where 

 the fossilization of their shells might ultimately be brought about. 



It is a well-known fact that birds frequently drop their eggs 

 during flight, or lay them, for some reason or other, in unusual 

 places * The eggs of such birds as Hawks, Owls (that breed in 

 hollow trees, &c.), and other forms, may occasionally, or rather 

 rarely, be deposited in this way, in situations where the subsequent 

 fossihzation of their shells be rendered possible. 



It will be as well to note, in passing, that manufactured " fossil 

 birds' eggs " are usually made by making a puncture of greater 

 or less extent in the egg of some domestic fowl (chicken. Duck, 

 Turkey, Guinea-Fowl, &c.), evacuating the contents, and then 

 filling the specimen with a mixture of plain gypsum and water, 

 or a so prepared cement which, when thoroughly hardened, has 

 the appearance and weight of a fossil of the same proportions. 

 After this the external surface of the shell is stained or otherwise 

 treated to imitate a smooth, fossilized surface — and the trick is 

 complete. These eggs have even deceived good palaeontologists, 

 especially when some plain, white egg of some wild bird-form has 

 been selected to perpetrate the fraud. Several such " fossil eggs " 

 have been examined by me ; but the nature of tl . specimen can 



* During the early part of the spring of 191 5. I was walking with my wife 

 through a field at Sunnyside, Maryland, when she found, among the thick 

 grass at her feet, the perfect and entirely fresh egg of a Blue-Bird (Sialia s. 

 sialis), which is still in her possession, having been carefully blown for her 

 by Mr. Edward J. Court, of Washington, D.C., who was with us at the 

 time. Now, had this bird dropped its egg in some soft mud or other, capable 

 of fossilization in time, and the egg had thus received such a fracture of its 

 shell as to admit of the escape of its contents ; and the ingress of the afore- 

 said fossilizable material having in time taken place, the specimen 

 ultimately settling down into the mud where it fell or was otherwise 

 deposited by the bird, the shell of that specimen might, in due time, become 

 thoroughly "fossilized, as would the material of its subsequent matrix be 

 similai-ly transformed. 



