FOOT OF THE HOUSE-FLY. 201 



draw from an examination of the foot of the 

 Lacerta Gecko. Sir Joseph Banks had mentioned 

 to him in the year 1815, that this lizard, which 

 is a native of the island of Java, comes out in the 

 evening from the roofs of the houses, and walks 

 down the smooth hard-polished chunam walls in 

 search of the flies which settle upon them, and 

 which are its natural food. When Sir Joseph 

 was at Batavia, he amused himself in catching 

 this lizard. He stood close to the wall at some 

 distance from the animal, and by suddenly scrap- 

 ing the wall with a long flattened pole, he was 

 able to bring the animal to the ground. 



Having procured from Sir Joseph a very large 

 specimen of the Gecko, which weighed 5f ounces 

 avoirdupois, Sir Everard Home was enabled to 

 ascertain the peculiar mechanism by which the 

 feet of this animal have the power of keeping 

 hold of a smooth hard perpendicular wall, and 

 carry up so heavy a weight as that of its body. 



kThe foot of the Gecko has five toes (as shown 

 in Fig. 62), and at the end of each of them, 



Fig. 62. Fig. 63. 



except the thumb, is a very sharp and highly- 

 curved claw. On the under surface of each toe 

 are sixteen transverse slits, leading to as many 



