234 HOW PARRAKEETS BREED. 



enriched by the innumerable droppings of the birds. The three 

 sides in which the holes are dug are so steep and precipitous that it re- 

 quires considerable agility to scramble along them, the danger of fall- 

 ing into the water being increased by the slipperiness of the soil, 

 worn smooth by innumerable feet, and continually moistened with 

 ordure. The sides are composed of soft, loamy earth, with rocks 

 of every size and shape jutting out in all directions, and afford the 

 most favorable possible conditions for the excavation of the bur- 

 rows. The fourth side between the two points is composed mostly 

 of masses of rock, in the crevices of which the auks chiefly deposit 

 their eggs ; they very often appropriate the deserted holes of the 

 puffins. 



" The holes in the ground in which the puffins deposit their eggs 

 (a habit, as far as I am aware, entirely peculiar to the genus in this 

 family of birds) are excavated by the birds themselves, an operation 

 for which their powerful beaks, and long, strong, and sharp claws 

 admirably adapt them. They extend nearly or quite in an horizon- 

 tal direction, and are semicircular in shape, with the diameter scarcely 

 larger than is necessary for the free passage of a single bird. They 

 vary much in length, but the majority are not so deep but that the 

 egg may be reached by thrusting in the arm to its full extent. 

 Their course is seldom in a straight direction ; they curve and wind 

 in a most tortuous manner, many burrows being connected to- 

 gether by winding passages. The entrances to the holes are worn flat 

 and smooth by continual paddling from the feet of the birds, and, 

 as well as the whole sides of the island, are moist and slippery with 

 the ordure. The sides of the island, just above high water mark to 

 the very top, are perforated with innumerable holes, but on the top 

 itself not a suigle burrow is to be seen. 



" At the further extremity of the hole, which is usually a little en- 

 larged, the single egg is deposited, always a slight bed of dried 

 grasses being first arranged to keep it from the moist earth. I 

 have indeed found eggs lying on the bare ground near the entrance 

 of the burrows, whither they had apparently been dragged by the 

 bird as it hurriedly made its exit ; but in no instance did I find one 



