Bird- Lore 



CROSSBILL 



AND 



HORNED LARK 



small birds whose diet consists largely of insects. Strictly insectiv- 

 orous birds, such as Swifts, Swallows and Goatsuckers, have a some- 

 what different tongue, — soft, fleshy, and beset, particularly about the 

 base, with numerous small backwardly directed points, whose office 

 is apparently to facilitate the downward career of food. That these 

 birds, so different in structure, as birds go, and members of families 

 so far apart in the bird world, should have similar tongues, seems 

 to indicate that the shape of the tongue bears a relation to 

 the character of the food, and gives no hint of correspond- 

 ing relationship between the birds themselves. 



The more exclusively granivorous birds have another 

 style of tongue, — smooth, thick, fleshy and but little frayed 

 at the tip, — a tongue which no doubt is useful for hold- 

 ing and husking minute seeds, while the little scoop-like 

 tongues of Goldfinches and Crossbills must be still more 

 serviceable for such purposes. 



The tongue of our common Goldfinch is furthermore 



beset about its edge with little hard points, and while 



these would add to its usefulness in gathering the fine 



seeds of thistles, yet, as thistles are only available for a 



part of the year, it is hardly probable that such a special 



modification is for such limited use, this being one of the 



cases where it is easier to make the theory fit part of the 



THE LITTLE facts than it is to make the facts conform to the theory, 



^GotD?rNCH^ My friend Mr. William Palmer has, however, offered a 



suggestion that seems to fit the case pretty well, calling 



attention to the fine, almost pasty condition of food found in the 



gullet of the Goldfinch, and suggesting that the small, hard points 



play a part in grinding up little seeds and reducing them to pulp. 



If we go back to the simple tongue with which we started, 

 stretch it out and feather it more deeply, we will have the pattern 

 of tongue that prevails among the Orioles ; or if we curve the thin 

 edges upwards and inwards until they meet, we will have a little 

 tube, such as is found among the Sunbirds and Honey-suckers. 

 In order that such a tongue may really suck, it is, of course, nec- 

 essary to create a vacuum at its back, and the muscles of the tongue 

 are so arranged that this can be done, the back of the tongue being 

 depressed, while the front or middle portion is in contact with the 

 roof of the mouth. Some of the American Honey-creepers {Ccvreba), 

 for example, have an interesting modification of this suctorial tongue, 

 the front portion being deeply cleft and the thin edges split and 

 rolled inward to form two hollow brushes. These may either dip 

 up liquid, or draw it inward by capillary attraction, while they are 



