86 



THE OOLOGI9T 



the sand, where they hatch out in due 

 course of time. The entire Order is 

 oviparous. 



"All lizards," says Dr. Gunther, "are 

 oviparous, the eggs being of an oval 

 shape and covered with a hard or 

 leathery calcareous shell. The num- 

 ber of eggs laid is, in comparison with 

 other reptiles, small, perhaps never 

 exceeding forty, and some, like the 

 anolis and geckos, deposit only one 

 or two at a time, but probably the act 

 of oviposition is repeated in these 

 lizards at frequent intervals. The par- 

 ents do not take care of their progeny, 

 and leave the eggs to hatch where 

 they were deposited. In a few lizards, 

 however, the eggs are retained in the 

 oviduct until the embryo is fully de- 

 veloped; these species, then, bring 

 forth living young, and are called ovo- 

 viviparous." 



What I desire especially to invite 

 attention to here is, that the eggs of 

 all lizards and chelonians are white, 

 the form of the first-mentioned being 

 ellipsoidal, and of the last named 

 more or less globular. Some serpents, 

 as the pythons, incubate their eggs by 

 surrounding them with coils of their 

 bodies. They also defend them with 

 marked fierceness against those who 

 attempt to take them. No turtle or 

 lizard ever does this, in so far as my 

 knowledge carries me. 



Eggs of the Crocodilia, or the croco- 

 diles and alligators, with their near 

 allies, lay elliptical eggs, with hard, 

 glossy shells, as in some birds. They 

 are buried in the earth by the female 

 and left to hatch out by the heat of 

 the sun. In color, these eggs are of 

 a creamy white, some of them quite 

 white, thus being, in this respect, 

 much more like the eggs of ordinary 

 birds than are those of any of the 

 other reptilian orders. 



In Pigs. 1-9 of this article, I give 

 some of the eggs of common bird, all 



of which are good examples of the 

 ovate form of them in this group, as 

 well as of the most unusual markings 

 of the "blotched" and "speckled" kind, 

 as we find them in such genera. No 

 reptiles of any species lay eggs which 

 at all resemble these, either in form 

 or otherwise. 



Some birds, however, do lay eggs of 

 an ellipsoidal form, or like those of 

 a great many reptiles, but the color 

 is present. This is the case with the 

 beautiful eggs of the Guira (Guira 

 guira) of Australia. A pair of these 

 are given in Pig. 10, they being a re- 

 production of my photograph of them, 

 and they belong to the superb collec- 

 tion of birds' eggs of Mr. Edward J. 

 Court, of Washington, D. C, who most 

 kindly loaned them to me for the 

 above purpose. They are of a rich, 

 pale, topaz blue, overlaid with a raised 

 network of a lace-like deposit of limy 

 substance. The eggs shown in Pigs. 

 1-9 are also from Mr. Court's and were 

 photographed by me along with many 

 others, which I propose to publish in 

 various connections. 



In going over birds' eggs, however, I 

 do meet with some which have the 

 exact form of eggs laid by certain rep- 

 tiles, as for example the globular eggs 

 of certain owls, which bear a close re- 

 semblance to the eggs of marine tur- 

 tles. Moreover, they are both white, 

 the chief difference being that the 

 shell of the turtle is leathery and flex- 

 ible, while that of the egg of the owl 

 is brittle and more or less chalky, as 

 in the case of the eggs of other birds. 



Mr. Court at one time had the egg 

 of a Barred Owl (Strix varia) in his 

 collection, which lacked but very little 

 of being a perfect sphere. This egg 

 I published a figure of in The Emu a 

 while ago, which is the ofllcial organ 

 of the Royal Australiasian Ornitholo- 

 gists' Union of Melbourne, Australia. 

 It was of natural size and a very beau- 

 tiful object. 



