Mr. Yarrell on the Beak of the Crossbill. 463 



'* between the scales, and then opening them, not in the usual manner, 

 *' but by drawing the inferior maxilla sideways, force open the scales 

 " or squamae. 



At this stage of the proceeding the aid of the tongue becomes neces- 

 sary, and this organ is no less admirably adapted for the service required. 

 The OS hyoides or bone of the tongue has articulated to its anterior extre- 

 mity an additional portion formed partly of bone with a horny covering, 

 figures 6 and 7, letter a. In shape it is narrow, about | of an inch in 

 length, and extends forwards and downwards, the sides curved upwards, 

 the distal extremity shaped like a scoop, somewhat pointed, and thin on 

 both edges, the proximal extremity ending in two small processes elon- 

 gated upwards and backwards above the articulation with the bone of the 

 tongue, each process having inserted upon it a slender muscle, h. figures 

 6 and 7, extending backwards to the glottis and attached to the os 

 hyoides, which muscles by their contraction extend and raise the 

 scoop-like point. Underneath the articulation of this horny and 

 grooved appendage is another small muscle, c. figure 7, which is 

 attached at one extremity to the os hyoides, at the other to 

 the moveable piece, and by its action, as an antagonist to the 

 upper muscles, bends the point downwards and backwards; while, 

 therefore, the points ot the beak press the shell from the body of the 

 cone, the tongue brought forward by its own muscle (genio-hyoideus) 

 is enabled, by the additional muscles described, to direct and insert its 

 cutting scoop underneath the seed, and the food thus dislodged is trans- 

 ferred to the mouth ; and it will be seen by a reference to the first 

 figure, that when the mandibles are separated laterally in this operation 

 the bird has an uninterrupted view of the seed in the cavity, with the 

 eye on that side to which the under mandible is curved. 



" The degree of the lateral power of these birds," says Mr. Townson, 

 *' is surprising, and they are fond of exercising it for mere amusement; 

 " they are therefore not- a little mischievous. 



" My pets would often come to my table, whilst I was writing, and 

 " carry off my pencils, little chip boxes in which I occasionally kept 

 " insects, and other similar objects, and tear them to pieces in a minute, 

 " Their mode of operation is by first pecking a little hole, in this they 

 " insert their bill, and then split or tear the object by the lateral force. 

 *' When I treated them, as I often did, with almonds in their shells, they 



