ART. 19 CONCERNING BIRDS ' TONGUES GARDNER 13 



flap connected with flexible lateral "horns." So far as has been 

 determined this is a form not approached by any other family of 

 birds and once having been seen is so characteristic that it could 

 not be confused with any other form, most especially with the storks 

 with which herons have often been classed and with which they 

 agree in feeding habits. It is long in Ardea herodias (fig. 32) and 

 shorter in Nycticorax nycticorax naevius (fig. 31) but with the same 

 general structure throughout, including Egretta candidissima., Cns- 

 merodius egretta, Botaurus lentiginosus (fig. 33), and Butorides 

 virescens anthonyi (fig. 34). 



Of great interest is the fact that in that odd-billed form the 

 boat-billed night heron {Cochlearlus zeledoni) the same structure 

 is preserved. The tongue is very short but is constructed exactly 

 as in the other herons, much as if the tongue of Ardea was cut to 

 the length of an inch or less. 



The storks {Ciconiidae) have rudimentary tongues, as do the 

 Ibididae (Threskiornithidae). Ciconia ciconia (fig. 26) has a flat 

 almost formless structure, while Plegadis guaraunu has one that is 

 very small but with some semblance of structure, as there are well- 

 defined spines present which, however, are flexible and functionless. 



The flamingoes (Phoenicopteridae) are characterized by fleshy 

 tongues supplied on the dorsum with conical spines and posteriorly 

 with a patch of spinose processes. These curl downward, as do the 

 bills. Figure 11 illustrates the tongue of Phoenicopterus I'uber. 



It is interesting to note that the four suborders are readily sepa- 

 rated by tongue form. The Steganopodes by rudimentary cylindrical 

 ones (except Fregata), Ardeae by their characteristic ones, Ci- 

 coniae by flat rudimentary, and Phoenicopteri by large fleshy 

 tongues. 



Order ANSERIFORMES 



The screamer {Ghauna chavaria) of the Palamedeidae has a flat 

 tongue with a single row of spines posteriorly not at all like the 

 Anatidae, but resembling more that organ in the gallinaceous birds. 



The Anatidae have a characteristic organ which, while modified in 

 response to diet, is readily recognizable as distinct from all others. 



Most mergansers have a long slender structure with but one row of 

 lateral hairs, while Mergus serrator (fig. 10) has a double row along 

 the entire dorsal surface. 



In Branta canadensis and B. nigricans, for tearing purposes, all 

 of the hairs of the two lateral rows have been converted into 

 strong backwardly directed spines, one row on each side, while 

 the dorsal surface is smooth, without the usual gutter. Such an 

 organ is incapable of much if any sifting. 



