457 



EAR. 



EBENACE.E. 



458 



which afterwards increases in length and becomes a tube. In the 

 adult the length of the whole tube mny be nearly an inch ; but from 

 the obliquity of the membrane, which faces a little downwards, it is 

 longer below than above. Its direction from the membrane is out- 

 wards and a little backwards, and it is slightly convex upwards, and 

 rather narrower in the middle than elsewhere. The last-mentioned 

 peculiarity is the reason why it is so much easier to introduce beads 

 and other round bodies (as children are apt to do) than to get them 

 out. This however must always be done as soon as possible when 

 such an accident happens ; for the presence of the foreign body some- 

 times excites great inflammation and swelling, and may lead to very 



Fig. 5. This is not to be considered as a correct delineation of the organ, 

 being intended only as a diagram, to give a general idea of the relative situa- 

 tions of the several parts : a, superior semi-circular canal ; 6, posterior ditto ; 

 r, external ditto ; d, seala tympani of the cochlea opened, to show r, the 

 fenestra rotunda, entering the tympanum under the promontory ; e, Eustachian 

 tube ; /, membrana tympani ; f, vestibule, not laid open ; m, meatos auditorius 

 externus ; n, mcatus internus, terminating in two fovefe. 

 serious consequences. The most easy method and the least painful is 

 to direct a strong stream of warm water into the tube with a syringe, 

 which commonly succeeds immediately if resorted to before there is 

 much swelling. Other means will readily suggest themselves ; but if 

 resorted to, they should be very tenderly used, for the part is extremely 

 sensitive, especially the membrane iteelf, to rough contact. The wax, 

 which is very bitter, serves to prevent the entrance of insects and to 

 keep the skin soft. When secreted too abundantly, it is often a cause 

 of deafness, and should be removed as a foreign body by means of a 

 syringe and a solution of soap in warm water. The commonest kind 

 of ear-ache is that caused by inflammation of this passage, and is 

 generally followed by a copious and foetid secretion poured out by 



Fig. 6. 



Fig. 0. View of the pinna, or auricle. The cartilaginous prominences are, 

 a, helix ; h, anti-helix ; rf, tragus ; e, anti-tragus ; the lobe or lobulus, g, con- 

 tains no cartilage, being composed only of skin and a fatty cellular tissue. The 

 depressions arc r, the scapha or scaphoid (boat-like) fossa ; and/, the concha, a 

 term oftrn used to denote the whole appendage of which it is the most 

 important part. 



the ceniminoim follicles. If this last long, deafness is sometimes the 

 result from thickening of the membrane, and has been removed, as 

 well as that arising from closure of the Eustachian tube, by punc- 

 turing the membrane. This part is sometimes ruptured by the 



spasmodic action of the tensor muscle caused by loud sounds, or by 

 driving air up the Eustachian tube in a forcible expiration, as in blow- 

 ing the nose violently. This accident is not followed by the degree of 

 deafness that might be expected, unless the stapes becomes displaced 

 from the fenestra ovalis : the other ossicula may be lost with com- 

 parative impunity for obvious reasons. 



The concha, or pinna, or auricle (for by all these names the outer 

 appendage of the ear is known), consists of several pieces of elastic 

 cartilage expanded in a form more or less resembling an ear-trumpet 

 in different animals. In man it serves the purpose of collecting the 

 sonorous vibrations and directing them into the meatus externus 

 much less perfectly than in many other animals, which are also pro- 

 vided with muscles for directing it to the source of sound, which in 

 man are but rudimentary. It is marked with various prominences 

 and hollows, of which the names are given in the figure. It does not 

 seem necessary to describe them more particularly. The cartilages 

 are bound by ligaments to the neighbouring prominences of bone, and 

 are covered by a smooth and closely adherent skin. 



It may be observed that the Aquatic Mammalia (Whales, Porpoises, 

 &c.) are unprovided with this part of the organ ; and have a very 

 narrow but long and curved meatus externus, passing obliquely into 

 the surface of the head, and in some instances capable of being closed 

 by a flap of moveable skin to exclude the water. In these animals 

 also the cochlea is imperfect, the scalse making but one turn and a half 

 round the modiolus. For an account of diseases of the ear, see DEAF- 

 NESS, in ARTS AND Sc. Div. 



(Scarpa, de Auditu; Blainville, Comp. Anat. ; Bell, Anatomy ; 

 Grant, Outlines; Pilcher, On the Structure, <hc. of the Ear.) 



EAR-SHELL. [HALIOTID.E.] 



EARTH-NUT. [BUNIUM.] 



EARTH-NUTS are either the fruit of certain plants which bury it 

 below the ground after the flowering is past, as the Arackit hypogcea, 

 Lathyrus amphicarpot, and others, or else the subterranean tubercles 

 of fleshy-rooted plants, such as Bulbocastanum, Cyclamen, Lathyrus 

 tuberosus, Apios tuberosa, and the like. 



EARTH-WORM. [ANNELIDA.] 



EARWIG. [FoRFicULiD*;.] 



EBENA'CE^E, Ebenads, a natural order of Monopetalous Exogenous 

 Plants with the following essential characters : Flowers either with 

 separate sexes, or occasionally hermaphrodite. Calyx permanent, 

 with from three to six divisions. Corolla monopetalous, regular, of a 

 thick leathery texture, usually downy on the outside, with the same 

 number of divisions as the calyx. Stamens twice or four times as 

 numerous as the lobes of the corolla, adhering to its tube, and usually 

 in two rows ; sometimes adhering in pairs. Styles several. Fruit 

 fleshy, superior, with only one pendulous seed in each cell. Embryo 

 lying in much albumen, with large leafy cotyledons and a long taper 

 radicle. The species consist entirely of bushes or trees, some of which 

 are of large size ; their leaves are alternate, with no stipules, and gene- 

 rally leathery and shining. They are chiefly Indian and tropical 

 species. A few occur at the Cape of Good Hope and in Australia. 

 This order is related to A quifoliacece, Oleacece, and Sapotacece. There 

 are 9 genera and 160 species. Dioapyrus Ebenua, and some others, 

 yield the valuable timber called ebony. The fruit of D. Kaki is about 

 as large as an apricot, and is dried as a sweetmeat by the Chinese. 

 Most of the plants of this order are tropical ; of the few found beyond 

 the tropics, D. Lotus inhabits Africa and Switzerland, and D. Virgini- 

 ana the United States. [DiosrYRUS.] 



A brunch of IHospynrs Lotus in fmit : 1, a flower ; 2, a corolla, crt f per. ; 

 3, the calyx and ovary ; 4, a section of a ripe fruit, showing the seeds. 



