210 British Birds, with their Nests and Eggs. 



is shared by both sexes, but it is usual to find only one bird upon the egg. 

 Probably the bird which is incubating is fed at night by its mate, which has 

 passed the day at sea. The egg of the Storm Petrel is believed to be incubated 

 for about thirty-five days. Mr. William Evans has ascertained that eggs of this 

 species when placed in an incubator chipped on the thirty-third day, while a chick 

 hatched out upon the thirty-fifth day. The nestling is at first covered with soft 

 greyish-black down. The late Mr. H. D. Graham once took two Storm Petrels 

 about a fortnight old, covered with a profusion of down, on the 8th of September. 

 They were at first fed with very small bits of fish, which they took reluctantly, 

 but soon developed a great partiality for cod-liver oil, and " would suck a stick 

 dipped in oil very willingly, clattering their bills and shaking their heads with 

 evident satisfaction. I should conclude from this that the Petrels feed their 

 young with the oil which they have the power of ejecting from their bills." 

 These nestlings became fledged about the middle of September, — when about three 

 weeks old, — supposing that they were two weeks old when obtained, — and became 

 much dissatisfied with confinement, though they still retained a great deal of down 

 upon their bodies. " Night and day their long powerful wings were in incessant 

 motion in their attempts to escape from the box. As soon as the lid is opened 

 they raise themselves up until they can hook their bills on to the edge ; and 

 then, assisted by their wings, and scrambling with their claws, they hoist them- 

 selves up. When upon the top of the box, they would be satisfied for a little 

 while, shake themselves, and dress their feathers. The instinctive love of motion, 

 however, would soon return, and they go off on a voyage of discovery. They 

 walk with great caution, keeping their heads down, and using their bills as 

 walking-sticks, hooking hold of any inequality to assist themselves along, and 

 keeping themselves up, for they have a constant tendency to topple over on their 

 faces : they also are of great service to feel their way, for their sight seemed 

 very imperfect, and their eyes were generally closed." [This we might have 

 anticipated, from the fact that this Petrel passes the first few weeks of its 

 existence in more or less complete darkness.] " When informed by the bill that 

 they are arrived at the edge of the table, the closed eyes open, and au anxious 

 survey is taken of the depth below, and after considerable preparation aud 

 thought, the hazardous leap is taken, and a short flight performed in safety 

 to the floor. These little birds seemed to have an irresistible instinct which led 

 them to attempt to surmount every obstacle which fell in their way. When 

 walking on the table every book and desk must be climbed by means of the 

 hooked bill, with the assistance of claws and pinions." Mr. Graham took another 

 young Petrel from its burrow on the 18th of October, when the bird was quite 



