414 DK W. AINSLIE HOLLIS. 



The latter cartilage in old birds becomes partially ossified. As. 

 regards range of movement, the angle through which the tip of 

 the cartilage can descend when the beak is carried horizontally 

 is probably not greater than 30°.^ The joint will not apparently 

 permit the upward elevation of the fore-tongue. There is, how- 

 ever, some lateral movement. In shape the cartilage is a sharp, 

 conical spicule about half-an-inch long, with the intrinsic 

 elevator muscle inserted on the upper surface of the proximal 

 end just beyond the joint. On the under side, about a line or 

 so from the point, are the insertions of the two long tendons (c c) 

 of the depressor muscles of the fore-tongue, one on either side. 

 These muscles originate on the inner surface of the greater 

 cornua. Besides these attachments, the lingual cartilage serves 

 to support the horny integument that covers the tip and under- 

 side of the fore-tongue, and it retains in position the mucosa 

 and the other structures which together make up that complex 

 resilient organ. 



I shall next briefly explain the action of these various 

 structures in the production of the hen's cluck. Before so 

 doing, however, I must draw attention to a widely-spread idea 

 amongst naturahsts, that a bird's tongue has nothing to do witb 

 the emission of notes, all such sounds being produced by the- 

 so-called syrinx. It will not be difficult, I believe, to show that 

 this statement, even if we exclude from its provisions the wellj 

 educated parrot, is far too sweeping in its terms, and that it 

 does not apply to the notes of a ' clocking ' hen. When the 

 hyoid bone of the fowl is pushed upwards, the tongue, which 

 usually rests between the rami of the lower jaw, is necessarily 

 pushed upwards also, for, as above stated, the anterior spur of 

 this bone is firmly imbedded in the root of that organ. If we 

 perform the above operation on a dead bird when the beak is 

 open, it will be seen that the upper surface of the tongue 

 glides over the roof of the mouth until the tip is about an 

 eighth of an inch in front of the anterior extremity of the 

 membranous slit which communicates with the nares in these 

 schizognathous birds. The dorsum now adapts itself closely to 

 the irregularities of the hard palate, or whatever represents 



1 In wild birds of this order {cjj. pheasants), the range of movement is probably- 

 greater. 



