76 NATURAL HISTORY 



vfiot pivcg, TtiavpiQ Trvotrjoi 8iav\oi." 

 " Quadrifidae nares, quadrupliues ad respirationem canales." 



OPP. CYH. lib. ii. 1. 181. 



Writers, copying from one another, make Aristotle 

 say that goats breathe at their ears ; whereas he asserts 

 just the contrary : " AAx/xa/wv ya% oux #Av^ Atyf/, (^ay^evoQ 

 uvci-isvF.iv rug u.iyct.<; uctrrot. TO. WT&" " Alcmaeon does not 

 advance what is true, when he avers that goats breathe 

 through their ears." History of Animals, Book I. 

 chap, xi. 2 



LETTER XV. 



TO THE SAME. 

 DEAR SIR, SELBORNE, March 30, 1768. 



SOME intelligent country people have a notion that we 

 have in these parts, a species of the genus mustelinum, 

 besides the weasel, stoat, ferret, and polecat ; a little 



2 There is more reason in the supposition that the ears communicate 

 with the nose, than that the suborbital sinus has any such communication ; 

 since in all animals that have a tympanic cavity opening upon the surface 

 by an external passage, there is also another conduit leading inwards 

 from the tympanum to the nose : this latter passage is termed the Eusta- 

 chian tube, and its office appears to be two-fold. First, it prevents the 

 membrana tympani or ear-drum, which is stretched across the external 

 meatus, from having its state of tension disturbed by the variation of the 

 pressure of the atmosphere upon its outer surface, by conveying the same 

 atmosphere to the tympanic cavity where it must press with equal force 

 against the inner surface of the ear-drum. Secondly, it serves, like the 

 lachrymal passage of the eye, to convey superfluous moisture to the nose. 

 When the membrane of the tympanum is accidentally ruptured, air may be 

 forced or expired from the mouth through the ear, but the Eustachian 

 passage is too narrow in mammals to admit of inspiration or breathing 

 being performed through the ears alone, even supposing the ear-drum to 

 be destroyed. In the natural condition of the parts the Stagy rite is, a 

 fortiori, correct in stating that goats cannot breathe through their ears. 



It is possible that the idea may have originated in the possession by 

 the chamois of post-auditory sinuses ; the openings of which behind the 

 base of the ears may have been regarded as orifices for breathing, in the 

 same manner as a similar function was erroneously ascribed to the 

 suborbital sinuses. R. O. 



