532 PHILOSOPHICAL TKANSACTIONS. [aNNO 16Q3. 



In the heads of parrots and paroquets, besides the first described passage, I 

 observed, between the two tables, every where cells opening into others, and 

 those into others, so that there was not any part scarcely of the skull that was 

 not occupied with them. And this did not only appear by pouring into one 

 ear freed from its drum, the other also being removed, a tincture of cochineal, 

 and then blowing it into all these cells, so that no part was free from tinc- 

 ture, but it appeared also to the naked eye, notwithstanding that sometimes it 

 was difficult to trace the communications of them by reason of the numerous- 

 ness of the laminulae and pillars. 



In singing birds, the structure of these passages is like that of the parrot 

 and paroquet, only that the pillars and laminulae are less than they should seem 

 to be in proportion to the heads. From whence it is probable, that these birds 

 are by this structure enabled to distinguish sounds and notes, and also imitate 

 them better, having a more musical ear. 



In the heads of pullets, geese, and ducks, I found only the first described 

 passage distinctly, but in plovers, bustards, and some others, I found another 

 that went over the sinus lateralis of the brain, from ear to ear. This seems to 

 be designed to make them more watchful than domestic fowl, or yet those that 

 live much on the water, because they are liable to many dangers, which the 

 others are exempt from. 



In the ears of all the fowl that I could examine, I never found more than 

 one bone and a cartilage, making a joint with it, that was easily moveable. 

 The cartilage had generally an epiphysis or two, one on each side, which were 

 very flexible, as itself was. The bone was small and very hard, having at the 

 end of it a broad but very thin plate of the same substance, on which it rested 

 as on its basis. I got that of a pullet's ear, represented in fig. 14, pi. 13, where 

 a is the main cartilage, and bb the two epiphyses, c the small bone, and d the 

 basis or broad end of it. In the figure also, part of the drum sticking to it is 

 represented, together with the cartilages. 



I observed three pair of nerves in all the broad billed birds, and in all such as 

 feel for their food out of their sight, as snipes, woodcocks, curlews, geese, 

 ducks, teal, widgeon, &c. These nerves are very large, equalling almost the 

 optic nerve in thickness, they begin a little more forward than the auditory 

 nerve from a little protuberance, which seems to be made for them ; one of 

 them goes over the optic nerve in the orbit of the eye, the other two go under 

 the eye. Two are distributed near the end of the upper bill, and are there 

 very much expanded, passing through the bone into the membrane, lining the 

 roof of the mouth. The third pair is distributed near the end of the lower 

 bill, and is subdivided like the former. Birds that pick their food where they 



