1010 



REPORT OF NATIONAL MUSEUM, 1895. 



front half of the tongue the character of a double tubeJ The base of 

 the tongue is formed by the soft, fatty, fibrous envelope of the basihyal, 

 which stretches like a mass of india rubber when the tongue is pro- 

 truded, and, like rubber, contracts when the tongue is retracted. 

 Immediately in front of this is the dense cartilaginous sheath of the 

 ceratohyals, forming the bulk of the tongue and practically consisting 

 of two portions — that investing the bony part of the ceratohyals and 

 that surrounding their cartilaginous prolongations. The ditferencc 

 between the character of the epidermis of these two parts is such tbat 

 in badly preserved or slightly macerated specimens the anterior part 

 may be slipped ofl" intact. If this is done, it will be found to be a 

 hollow tube of cartilage, grooved along the middle above and below, 

 and slightly grooved along the upper, outer surface. This tube is soon 

 divided by a vertical partition, while a little more than halfway 

 between base and tip the tongue forks, each branch continuing hollow 

 for some distance. A fold, or flange, commences near the base of the 

 tongue, on either side, and continues to the tip, growing wider and 



Fig. 7. 



thinner as it proceeds, until along the branches it becomes a very deli- 

 cate membrane. As previously stated, it is these two membranous 

 portions which become rolled into tubes, and when the tongue of the 

 humming bird is spoken of as being tubular, it is these branches which 

 are meant. To say that the tongue consists of two iiarallel muscular 

 tubes is quite erroneous, as is the statement that the tubular portion of 

 the tongue is drawn back into a muscular sheath. It seems a little 

 doubtful if the tongue of the humming bird can be a true suctorial 

 tongue, for the tubes formed by the anterior part of the tongue are not 

 long enough to reach the back of the mouth, neither are they tight 

 along the edges,~ although, owing to their small size, liquid would 

 undoubtedly rise in them by capillary attraction. Gosse, who observed 

 these birds in confinement, seems to furnish the clue to the action of 



' Much confusion and bickering have been caused by more or less loose descriptions 

 of humming birds' tougnes, unaccompanied by good explanatory figures, and it has 

 been vigorously asserted, and quite as vigorously denied, that the tongue of the 

 buinming bird was bollo-w, or tubular. 



