LIFE HISTORIES OF I>rORTH AMERICAN PETRELS AND PELICANS. 179 



larger end. with dark red and purplish dots, but some few were equally spotted 

 all over the shell, while one was almost entirely devoid of marliiugs. In shape 

 they vary considerably, some being perfect ovals equally round at both ends, 

 while others are slightly pointed at the one end. Both sexes take part h\ 

 incubation, for out of twelve birds captured on the egg three were males. 



Eggs. — Mr. Henry O. Forbes (1893) describes the single egg as 

 "elliptical in shape. Ground color white, at one end covered with 

 fine dots of heliotrope-purple and lavender-grey, with a few of seal 

 brown interspersed, and at the other end sparsely with vinaceous 

 buff. In some specimens the end is thickly dusted over with the 

 finest vinaceous-rufus dots, while on the rest of the egg they are 

 scarcely recognizable." Buller (1888) and Gould (1865) describe 

 the eggs as ''pure white.'' Campbell (1901) gives it as follows: 

 " Texture of shell comparatively fine ; surface occasionally has a 

 faint trace of gloss; color, pure white, but about 50 per cent have 

 numerous fine brownish freckles about the apex." 



The measurements of 22 eggs, sent me by Rev. F. C. R. Jourdain, 

 average 36.20 by 22.03 millimeters; the eggs showing the four ex- 

 tremes measure 37.4 by 26.5, 36.9 by 27 A, 33.8 by 25.7, and 37 by 

 25.4 millimeters. 



Young. — Several observers have noted that both sexes incubate. 

 The period of incubation does not seem to be known. Mr. Robert 

 Hall (1902) gives us the following good description of the downy 

 young, partly fledged: 



Except the chin and throat, the whole under surface is covered with a 

 sooty-grey down averaging more than an inch in length. The down has fallen 

 from the upper surface, excepting the crown and rumi). The back is deeper 

 .slate colored than in the adult, and the wings, which are almost free from 

 down, are of the .same color; the hind neck is mottled with white; the face is 

 deep slate colored ; the lores white with dark tips ; the chin, throat, and cheeks 

 white ; the feet slate colored, with a very light yellow mark between the toes ; 

 the bill is dark. The bulk appears to be t^^^ce that of the adult. Girth of 

 nestling at shoulders 10.5 inches ; of adult, 4.5 inches. 



Plumages. — Godman (1907) says that "the plumage of full-grown 

 3"oung birds is like that of the adults as soon as the down is shed. 

 The grey rump and upper tail coverts have wavy cross lines of 

 grey and white, with a white fringe at the end of the feathers. One 

 specimen has the lower flanks and under tail coverts freckled with 

 greyish bars." 



Food. — The only reference I can find to the food of the white- 

 faced petrel is what I have quoted above from Campbell and Mat- 

 tingley, that " up to the final stage the parents feed their offspring 

 nightly with about a teaspoonful of fishy, oily paste, principally 

 composed of ' whale's food,' a small species of crustacean found 

 floating on the surface of the ocean." 



