192 HABITS OF BIRDS. 



the hilarity of the former. This little bird sings 

 likewise in the spring."* 



The researches of comparative anatomy have 

 thrown much light upon the peculiar structure of 

 song-birds, though there remain still many points of 

 interest for future investigation. This, indeed, was 

 a subject taken up by the earlier naturalists, and 

 most of their observations have been subsequently 

 confirmed and extended. Among other curious facts, 

 it is stated in Clayton's Letters from Virginia, that 

 Dr. Moulin discovered that. in birds, contrary to 

 what takes place in man and in quadrupeds, there 

 is almost a direct passage from one ear to the other ; 

 so that, if the drum (tympanum) of both ears be 

 pierced, water, when poured in, will pass from the 

 one to the other. There is no spiral shell (cochlea), 

 but a small passage which opens into a cavity form- 

 ed by two plates of bone that constitute a double 

 scull all round the head. The outer plate of bone 

 is supported by many hundreds of small threadlike 

 columns, or, rather, fibres. Now this passage was 

 observed to be much larger in singing-birds than in 

 others that do not sing ; so very remarkably so, that 

 any person to whom the difference has once been 

 shown, may easily judge by the head what bird has 

 the faculty of singing, though he may be otherwise 

 ignorant of its habits. f We have not seen any 

 notice of this singular circumstance by any other 

 inquirer. 



The remarks of Syme upon this subject are ap- 

 propriate and, so far as we know, correct. " The 

 notes," he tells us, " of soft-billed birds are finely 

 toned, mellow, and plaintive ; those of the hard-bill- 

 ed species are sprightly, cheerful, and rapid. This 

 difference proceeds from the construction of the vo- 

 cal organs. As a large pipe of an organ produces 



* Journal of a Naturalist, p. 265, 3d edit. 

 f Miscellanea Curiosa, iii., 291. 



