JAMES NE WTON BASKE TT. 95 



of the habit being hurtful, it will in time influence morphologi- 

 cal structure. As it now stands, the Raptores may be, except 

 in extent, a group nearly as artificial as the old Natatores. 



It would be interesting, if space allowed, to mention a 

 few of the other influences that have affected eggs. As 

 already hinted, aside from shape and shell, the embryonic 

 history of the egg is very hmited. The bird inherits it 

 from the saurian hard-shelled, with little left to modify but 

 shape and color. The swing of variations in this is small 

 — especially in the shape ; and much as eggs differ in color, 

 it will readily be noted that the differences are wrought with 

 small variety of material. It is more a permutation than 

 anything else. On these permutations specialization has 

 seized, in keeping with the modifying demands of color- 

 protection, parental safety, reversions, and what, perhaps, 

 Mr. Wallace has suggested as unlicensed variation, not 

 influenced by anything. In such groups as the old Ficarice 

 the egg has perhaps stood still near to its saurian type, or 

 else gone a round of reversions that have brought it back. 

 Should this latter be the case, what a pedigree of bloods, 

 or map of life-routes, a plain, untinted, unmasked egg might 

 be ! Through this old group the beak has ranged from the 

 saurian shape of the parrots to the highly specialized tool of 

 the woodpeckers, and the toes have gone from simple rever- 

 sions and groupings in pairs to permanent solderings and 

 degenerations in loss of joints. Evidently these adhesions 

 are in no way connected with primary swimming mem- 

 branes. If the eggs have simply remained white, there is 

 nowhere among birds a better illustration of specialization 

 remaining dormant in them while it ran rampant in struct- 

 ure and habit. 



Primarily the eggs of birds must have been white, from 

 the inherent color of the salts of lime and magnesia of the 

 shell. At least this must have been the case with the eggs 

 of the reptiles. As their eggs were buried out of sight there 

 was no demand for significant coloration. 



