142 



Lucas, Tongue of the Cape May WarbUr. 



r Ault 

 L April 



is changed by internal and external conditions, that such organs 

 as the tongue and viscera would be more easily influenced, 

 especially by any change, either from choice or necessity, in 

 the character of a bird's food. If this be so, we should find 

 differences between these parts in neardy related birds, while at 

 the same time it should not surprise us to discover resemblances 

 between them among forms separated by space, or skeletal 

 structure, but whose food habits are similar. 



Coereba coerulea and C. cyanea are certainly near relatives, 

 and their skulls are so much alike that I doubt my ability to 

 tell them apart, but their tongues, although the same in struct- 

 ure, differ so decidedly that they may be distinguished from one 

 another at a glance. Unfortunately, for lack of material, I can 

 carry the subject no farther and am unable to say whether or 

 not the tongue of ccerulea is typical of the plainer colored species. 

 Now about as far from America as one can readily get, in New 

 South Wales, we find that one of the Honey-suckers {^Acantho- 

 rhynchus tenuirostris) has a tongue structurally like that of 

 Ccereba, but elaborated and refined to a greater degree, being 

 more slender, more tubular, and more finely feathered. Judged 

 by cranial characters the two birds are widely separated, for, as 

 Dr. Parker has pointed out, the palate of Acanthorhynchus has 

 a feature in the relations of the premaxillaries and palatines 

 found in the Ostrich but exceptional higher up the scale. Com- 

 ing back to America, to the genus Dendroica, we will find 

 that while the tongues of various species are constructed on the 

 same plan, that there is great specific variation in the execution 

 of details, the extremes, so far as I have examined, being 

 marked by Dendroica maculosa and D. tigrina^ and that 

 while these extremes are widely separated, yet the gap between 

 them is bridged over by other species which show intermediate 

 stages. The Tanagers, too, show considerable diversity in their 

 tongues, some being thick and fleshy, others thin and horny, 

 while there is much less uniformity of plan in these birds than 

 in the Warblers. While these facts are entirely too few to form 

 the basis of a reply to the question, What is the value and con- 

 stancy of pattern of the tongue.? they seem at least to hint that 

 while there may be a certain general structural plan in a given 

 group of birds, that this plan is subject to great s^^ecific varia- 



