NOTE-BOOK OF A NATURALIST. 141 



gradually a quantity of decaying vegetables, tlie bird 

 makes a hotbed. Several weeks are patiently employed 

 in bringing the materials together, till, at length, a 

 mound, consisting of a congeries of from two to four cart- 

 loads, is formed. But it must not be considered as the 

 labour of an individual, or of a pair, for many join in the 

 work. When once established, a forcing-bed of this de- 

 scription does duty for many years ; that is, the same site 

 is resorted to, and as the lower part decomposes the birds 

 superadd an additional supply previous to depositing their 



eggs. 



In the construction of the most elaborate of bird's- 

 nests the bill is the principal instrument of action, the 

 feet performing a very subordinate part in the operation. 

 In the instance before us the case is reversed. The foot 

 is the agent in collecting and depositing ; the bill is not 

 used for those purposes at all. The bird grasps a quan- 

 tity in its foot, throwing it backwards to the common 

 centre of deposit. The surface of the adjoining ground 

 is thus cleared for a considerable distance so completely 

 that hardly a leaf or blade of grass is left. When this 

 pyramidal vegetable mound has had a sufficient time to 

 heat, so as to be of the proper temperature, the large 

 eggs are inserted, not side by side as in ordinary cases, 

 but planted at regular distances from each other, some 

 nine or twelve inches apart, perfectly upright, and with 

 the large end downwards, each egg being buried at nearly 

 an arm's depth. They are then covered up and left till 

 they are hatched. 



John Hunter found the temperature of a sitting hen 

 to be 10J?° of Fahrenheit's thermometer, and ascertained 

 the heat to be the same when the ball of the instrument 

 was placed under her. Having taken some of the eggs 

 from under the same hen, when the chick was about 

 three-parts formed, he broke a hole in the shell, and in- 

 troducing the ball of the thermometer he found that the 



