Journal of morphology . lus {s) capsule, and viewed from the out- of anatomists. From the utricular ^^^- ^^^ somewhat diagram- T , ... , , matic figure represents the ear chamber near its iunction with the , . ? •. , • J about twice its natural size, as endolymphatic duct is given off a found in a fish five feet in , short and relatively narrow, -4«, anterior ampulla; a*, anterior which soon enlarges into the anterior ^^^^^^^ ^^ ^^^^^^-^^ ^-^^^^ , en- . dolymphatic canal; co, utriculo- canal complex (,r); similarly, from the ^^^^^^^^ ^^^^. ^.^ ^^^^^^^^ ^^. sacculus, but further d
Journal of morphology . lus {s) capsule, and viewed from the out- of anatomists. From the utricular ^^^- ^^^ somewhat diagram- T , ... , , matic figure represents the ear chamber near its iunction with the , . ? •. , • J about twice its natural size, as endolymphatic duct is given off a found in a fish five feet in , short and relatively narrow, -4«, anterior ampulla; a*, anterior which soon enlarges into the anterior ^^^^^^^ ^^ ^^^^^^-^^ ^-^^^^ , en- . dolymphatic canal; co, utriculo- canal complex (,r); similarly, from the ^^^^^^^^ ^^^^. ^.^ ^^^^^^^^ ^^. sacculus, but further down on its pulla; Ht, external canal; mu,body, is given off a tube which opens macula utriculi, auct.; /, lagena into the posterior canal (z). This ^^ P?^^ ^-^ ^ ^^^^^ pore of endolymph canal; s, its ear, then, shows very plainly the two g^^. p^^ posterior ampulla; P^, chambers usually described as SUpe- posterior canal; ^C, sacculus and rior and inferior divisions of the ear its macula sacculi; f/ and £/,. utriculus and utriculo - saccularchamber. cavity, or the utriculus and sacculus, and it is perfectly evident that these chambers are not superposed, but placed one beside the other in an antero-posterior direction. The utricular and saccular chambers are nearly equal insize in Dasyatis; but in most other Elasmobranch forms, as lO AVERS. [Vol. VI. well as in all the higher groups, there is a varying dispropor-tion, the sacculus becoming in general the larger of the twochambers. In the Cyclostomata, as one would expect, these chambers arevery nearly equal in size, and in some forms are scarcely sepa-rated from one another. In Dasyatis the sacculus is drawn outbackwards, downwards, and outwards, into a curved blind pocket(/.), the lagena. The utriculus in this species does not show asimilar pocket, though it is well developed in some Elasmo-branch fishes, and the sense-organ differentiation connectedwith it variously indicated in many of the higher forms. Theanterior cana
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Keywords: ., bookauthorwistarin, bookcentury1800, bookdecade1890, bookyear1892
