464 Mr. Yarrell on the Beak of the Crossbill 



" got at the kernel in the same manner ; first pecking a hole in the shell, 

 " and then enlarging it by wrenching off pieces by the lateral power." 



Notwithstanding M. Buffon's assertion to the contrary, they can pick 

 up and eat tlie smallest seeds, and they shell or husk hemp and similar 

 seeds like other birds ; so well contrived and useful is this singular beak. 

 My friend Mr. Morgan kept a pair of these birds for some time, and had 

 opportunities for observing their curious habits. They were impatient 

 under coijfinement, and restless, climbing over the wires of their cage by 

 the use of their beak and claws like parrots. One of their principal oc- 

 cupations was twisting out the ends of the wires of their prison, which they 

 accomplished with equal ease and dexterity. A short flat-headed nail that 

 confined some strong net-work was a favorite object upon which they 

 tried their strength; and the male, who was usually pioneer in every new 

 exploit, succeeded, by long continued efforts, in drawing this nail out of 

 the wood, though not without breaking off the point of his beak in the 

 experiment. Their unceasing destruction of cages at length brought 

 upon them sentence of banishment. During the period of their captivity 

 a complete change took place in the colour of their plumage without the 

 shedding of a single featlier. 



The remarks of Buffon on the beak of this bird, which he characterizes 

 as " an error and defect of Nature, and a useless deformity," exhibit, to 

 say the least of them, an erroneous and hasty conclusion, unworthy the 

 spirit of the science he cultivated. During a series of observations on 

 tlie habits and structure of British birds, I have never met with a more 

 uiteresting or beautiful example of the adaptation of means to an end, 

 than is to be found in the tongue, the beak and its muscles in the 

 Crossbill. 



Explanation of the Plate. 

 Fig. 1. Head of the Crossbill; side view. a. temporal muscle; b. great 

 pyramidal muscle. 



2. Head viewed from below, b. great pjTamidal muscle; c. c. 



pterygoid muscles ; d. d. graciles muscles. 



3. Head viewed from the side ; a. ptery^goid process ; b. os 



omoideum; c. os quadratum; d. d, os jugale. 



