Their Mocking Birds may be compared to our Singing Thrushes, being much of the same bigness; there are two sorts, the Gray and the Red, the gray has Feathers much of the colour of our gray Plovers with white in the Wings like a Magpye; this has the much softer Note, and will imitate, in its singing, the Notes of all Birds that it hears, and is accounted much the finest Singing Bird in the World. Dr. _Moulin_ and I made in our Anatomy many Observations of Singing Birds to this effect: The Ears of Birds differ much from those of Men or Beasts, there's almost a direct passage from one Ear to the other of Birds, so that prick but the small Membrane call'd the Drum on either Ear, and Water poured in at one Ear will run out at the other: But this is not all, but what is much more remarkable, they have no Coclea, but instead thereof there's a small Cocleous or twisting Passage that opens into a large Cavity, that runs betwixt two Sculls, and passes all round the Head, the upper Scull is supported by many hundreds of small Thred-like Pillars or Fibers, which as we supposed had another use also, to break the Sound from making any confused Echo, and to make it one and distinct; this passage we observed betwixt the two Skulls was much larger in Singing Birds than in others that do not sing, so very remarkable that any Person that has been but show'd this may easily judge by the Head what Bird is a Singing Bird, or has aptitude thereto, tho' he never saw the Bird before, nor knew what Bird it were: This has often made me reflect how much the Modification of Voices depends upon the accuracy of the Ear, and how deaf Persons become Dumb: And since I have observed that many Children that have an acute Wit enough that are slow of Speech, that is long before they speak are much longer before they can pronounce those Letters that are sharps, as _g._ _h._ _r._ and never have an aptitude to learn to sing. Hence I judge that Songs that have many Sharps in them are the difficultest to sing well, and discover any Persons skill upon the trial of Musick most. This I suppose only, having no Skill in Musick my self, nor having ever discoursed any Person about it. As I remember we show'd some of these things to the _Royal Society_, and I drew some Cuts thereof, and gave the Doctor upon promise that he would put these and many other our joint Observations in Print, but I hear he is since dead. I have Anatomized most sorts of Creatures, and never found any Four-footed Creature with an Ear like a Bird, unless a Mole; and a Mole has an Ear much like them, with a very thin double Scull, and great Cavity like a Bird, and is very acute of hearing, the Scull by reason of the large Cavity is very slender and easily crush'd, so that a Mole is quickly kill'd with a bruise on the Scull like a Lark, and upon the bruise the Membranes of the Scull turn black; whence _Segerus_ mistake _Membranæ Cerebri in superficie exteriori omnino nigræ visæ_. But when