6 PROCEEDINGS OF THE NATIONAL MUSEUM vol.67 



121) modify this by having six or seven tangled tips well calculated 

 to collect small insects and spider eggs from the crevices of tree bark. 



Such, in brief, is a survey of the modifications of the type pattern 

 seen among birds. There are, however, many tongues that are ap- 

 parently fashioned on other foundations. Among these are found 

 many of the shore and water birds. Thus the tongue of a gull (fig. 

 28) (Larus) might be selected as a type. In these forms, according to 

 Giebel,® the ceratohyals tend to fuse into one bone. Superficially 

 one sees this manifested by a rather fleshy organ which, while having 

 a median depression or groove running the length of the tongue, still 

 has no tendency to curl and, while often very slightly incised or 

 frayed at the tip, is not split to any degree. Such a tongue, varying 

 in length and breadth, is to be found in a large series of rails, sand- 

 pipers, terns, plovers, and the like. 



Some interesting adaptations are to be noted especially among the 

 fish feeders. If the tongue is edged laterally with sharp spines for 

 one-half or more its length we would have it as seen in the petrel 

 tribe, fulmars (fig. 25) and shearwaters; loons (fig. 23) modify the 

 pattern by concentrating all the spines in one large sharp patch 

 posteriorly. Finally if this process is continued so that the whole 

 surface of the tongue is covered with retroverted spines we would 

 have the condition as represented by the penguins. 



Another ground pattern is seen among the woodpeckers (fig. 13). 

 As has been noted the basihyal has been greatly lengthened in these 

 birds whereas the ceratohyals are fused as a small conical tip. The 

 true tongue then is represented by the sharp horny white tip armed 

 with lateral, backwardly directed spines, while behind this is the 

 long extensile wormlike basihyal portion which, when drawn back 

 into the mouth, inverts and forms a sheath into which the rest of 

 the organ can be retracted. This portion is covered with minute 

 spines scarcely visible to the unaided eye, the apparent function of 

 which is to hold the saliva, which is especially abundant in these 

 birds. This pattern is characteristic of the family Picidae and is 

 seen in no other forms. 



An odd pattern is assumed by the Ardeidae (figs. 31-34) in which 

 it is long, fleshy, and cylindrical, the characteristic feature being, 

 however, the absence of sharp spines at the posterior margin of the 

 tongue. Instead is found only a soft, fleshy flap, somewhat ser- 

 rated in outline, ending laterally in large but flexible tips. 



Among the Anatidae (fig. 9) again this organ assumes a char- 

 acteristic appearance undergoing many interesting variations to 

 be described later. 



« Giebel, C. Die Zunge der Vogel und ihr Geriist, Zeitschr. fur die Gesammten Natur- 

 wiss., vol. 11, 1858, pp. 19-53. 



