File:Journal of morphology (1892) (14596360908).jpg

Identifier: journalofmorphol1892wist (find matches)
Title: Journal of morphology
Year: 1892 (1890s)
Authors: Wistar Institute of Anatomy and Biology
Subjects:
Publisher: Philadelphia, Wistar Institute of Anatomy and Biology
Contributing Library: Harvard University, Museum of Comparative Zoology, Ernst Mayr Library
Digitizing Sponsor: Harvard University, Museum of Comparative Zoology, Ernst Mayr Library

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ynchus, butontogenetically this is not the case; for in the ears of theembryos of Man, Ox, Pig, Rabbit, Mouse, and Cat, the organhas scarcely begun its histological differentiation at the timewhen the adult condition, as regards number and form of thespiral turns of the cochleartube, has been attained. Mainly on account of thegreat development of the brainin the human species morethan in any other Mammal,and the consequent alteredrelations of the cranial bones,the vertical axis of the lowervertebrate ear is shoved toone side, so that in Man, forexample, it is directed fromwithin, below, and in front —outwards, upwards, and back-wards. In keeping with thischange is the alteration in thedirection of the horizontal axisof the lower vertebrate ear, sothat in Mammals it comes tonearly coincide with the verti-cal axis; in other words, therehas been a revolution of the ear on two of its axes, the mainchange having taken place by a revolution of nearly 90° in theplane of the vertical axis.
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cr.o.poat- Cut 24. ■See explanation of PI. IX,Fig. 3- 2IO AYERS. (Vol. VI. The nerve end organs of the human ear are six in number. 1. Macula acustica recessus utriculi. 2. Crista acustica ampuUse anterioris. 3. Crista acustica ampullae externalis. 4. Crista acustica ampullae posterioris. 5. Macula acustica sacculi. 6. The mammalian cochlear organ, or Cortis organ. The two nerve end organs possessed by most all Vertebratesfrom the fish up to Mammals are thus seen to be wanting inthese latter,—viz. macula acustica neglecta and papilla acusticalagenae cochleae,^—while the important sense organ of thecochlea of Saurians has disappeared in the adult, though fully-developed in the embryo, and functionally perfected before thecompletion of Cortis organ, which supplants it. E. Phylogenetic Considerations. Ich sagte, es sei mir gelungen, einen Grundplan des Gehororganes der Wirbel-thiere, das Wesen des Baues desselben festzustellen. Dieser einfache Plan muss nunnach dem grossen in die W

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