1018 REPORT OF NATIONAL MUSEUM, 1895. 



l)ointed, little compressed beaks, not well adapted for cutting into wood, 

 and the members of the genus Melanerpes are seemingly more fond of 

 fruit than are any other species, and they are the most omnivorous 

 of the IS'orth American woodpeckers. 



In all these cases the relation between form and food is plain, but 

 there are many others in which peculiarities of the tongue imply modi- 

 fication for some special end without that end being obvious. Such is 

 the case with the penguins, whose curious spiny tongues (fig. 12) must 

 play some definite part iu their domestic economy, but whether modified 

 for the catching of fish, crustaceans, or squids is not quite clear, 

 although such tongues would seem to be well adapted for catching 

 small crustaceans. 



The tongues of our American vultures too should have some bear- 

 ing on their diet, and possibly their hollow shape and roughened edges 

 are for the purpose of rasping meat from bones, although it may be 

 that the adaptation is to quite a different end. The long, slender, 

 feathery tongues of toucans present another riddle which can only be 

 answered by one having full knowledge of their habits, although it 

 certainly seems a curious adjunct to the stout beak with which it is 

 associated. 



From what has been said above it will be seen that, in a large num- 

 ber of cases, there is certainly a clear relation between the shape of the 

 tongue and the character of the food ; that some closely related birds 

 differ as to their tongues while distant relatives present similarities 

 that seem to be connected with similarities in their food, and that, on 

 the whole, the modifications of the tongue appear to be adaptive and 

 do not offer characters that can be safely used in classification. 



A final point, deserving of study, is that of the changes which take 

 place during growth and the rapidity with which they are performed. 

 As is well known, the bills of long-beaked birds are acquired after 

 hatching, and long tongues grow in a like manner, such a slender, exten- 

 sile tongue as that of the humming bird being developed between the 

 time the young emerges from the egg and the date of quitting the 

 nest. The first indication of the long branches into which the tongue 

 is ultimately divided consists of a little notch in the tip, while there is 

 only the merest rudiment of the membrane which is to border these 

 branches (Plate 2, figs. 10-13). 



The growth of the tongue, and of the hyoid as well, must be quite 

 as rapid iu woodpeckers as in humming birds, for in a full-fledged 

 nestling of the downy woodpecker, a species which is provided with 

 one of the longest of tongues when adult, the hyoid barely reached 

 to the center of the skull, between the eyes. The same specimen 

 showed also that the barbs at the tip of the tongue are developed com- 

 paratively late, for the only trace of spines in this bird, which would 

 have soon quitted the nest, was a number of reflexed hairs represent- 

 ing the upper series on the tongue of the sapsucker. It seems prob- 



