ORGAN OF SMELL IN MAMMALIA. 



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by the surrounding air sinuses, Avhich pervade every bone of the 

 cranium. The bony nasal passage is continued in almost a 

 straight line from the anterior aperture, a, to the posterior one, 

 1. The vomerine part of the septum, 1.3, extends from the pre- 

 sphenoid about half-way to the anterior aperture. At the upper 

 part of the cavity, so divided, the ethmoturbinals are situated, 

 which are moderately plicated : the maxillary turbinal is, also, 

 comparatively simple in character. 



In the Tapir the shorter proboscis terminates by a small 

 pointed extremity between the nostrils. The snout is covered 

 with hair to the base of the terminal appendage ; the hair on the 

 upper part tending upward or backward, that on the sides toward 

 the tip. The cribriform plate is not simply perforate, but is re- 

 ticulate, with long radiating meshes, the latter closed by dura 

 mater : it sends down curved lamellrc, sheathing the olfactory 

 nerves. The ethmoturbinal consists of as many convolute divi- 

 sions attached to, or continued from, those processes, in a pedun- 

 culate way ; and each is perfo- 

 rated bv many foramina through 



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which branches of the olfactory 

 pass to the pituitary membrane. 

 The maxillary turbinal is elon- 

 gate and simply convolute. 

 The nasal cartilages show the 

 chief modification, the alar 

 portions, fig. 155, n, being 

 continued backward, expand- 

 ing, and filling the peculiar 

 grooves of the skull (vol. ii. 

 p. 449) between the nasal bones 

 and orbits, o : here the cartilages are semiconvolute, convex, and 

 entire outwardly, excavated on the inner side, the cavity being 

 continued by a groove into the nasal one at the sides of the outer 

 aperture : from the character of the lining membrane, it may be 

 regarded as an extension of ' Jacobson's fossa.' The ' levator 

 rostri,' or raiser of the short proboscis, fig. 155, a, arises from the 

 process of the lacrymal, runs in a fibrous sheath, couvero-ino- to 

 its fellow, and is inserted into the upper or fore-side of the part 

 which, together, they raise, or, acting separately, draw to their 

 own side. A broader muscle, ( retractor labii,' Z>, from the same 

 origin expands to its insertion at the side of the labial part of the 

 base of the proboscis. Beneath this is the muscle, c-, which 

 rising from the lower border of the lacrymal, spreads upon the 



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Alinasal cartilage - and muscle.? of trunk, Tapir. 

 xcni". 



