TONGUE OF THE GREEN WOODPECKER. 57 



may say, must soon be generally practised ; but as we have a 

 good opportunity, we may take the measurements of the bird: — 

 Length loh inches, extent of wings 20 ; wing from flexure 65 ; 

 tail 4/g ; bill along the ridge Ij^, along the edge of lower man- 

 dible 1 1 § , width of mouth |^g ; tarsus 1 1% ; hind toe/jj, its claw ^% ; 

 second or inner toe j%, its claw -{'^^ '•> third 1 inch, its claw /^ '•> 

 fourth or reversed toe j%, its claw jly. There are six scutella on 

 the tarsus, four on the first toe, nine on the second, twelve on 

 the third, and eleven on the fourth. Now for our dissection. 

 Here the bird is laid on its back, the integuments are removed 

 from its breast, neck, and head ; and the parts are before us : 

 the mandibles, the tongue, the hyoid bones, the salivary glands, 

 the trachea, and its muscles. See Plate XV. 



Our principal object is to trace out the apparently complex 

 apparatus by which the tongue is protruded and retracted. 

 Two slight diagrams will afford a sufficiently correct idea of the 

 mechanism employed, which is extremely simple. Let Fig. 1, 

 a b, be an object or instrument, which is to be carried forward 

 a certain distance, and then drawn back. All that is neces- 

 sary is to lengthen it behind, a c, fix a cord to the end or to 

 some part, c d, pull this cord, and by means of another cord, 

 a e, restore it to its original position. As the elongated part 

 or appendage cannot in a bird project straight backwards, for 

 then it would pass through the vertebras and spinal marrow, 

 it must be split into two, one-half passing along each side of 

 the neck ; and as the length of this part must correspond to 

 the distance to which the tip of the tongue is to be protruded, 

 it becomes necessary to dispose of it so as not to impede the 

 functions of the neighbouring parts, and thus it may conveni- 

 ently be curved over the head, between the skull and the skin. 

 Fig. 2 represents such an instrument, it being merely Fig. 1 

 modified : a b, the tongue ; a c, its double appendage ; d c, 

 the muscles or cords by which it is pulled forward ; a e, those 

 by which it is brought back. 



Now, the tongue of this Green Woodpecker, when examined 

 superficially, in its retracted state, presents the appearance of a 

 slender, cylindrical, somewhat tapering, fleshy body, termi- 

 nated by a slender, flattened horny point, of which the upper 



