ORGAN OF SMELL IN MAMMALIA. 215 



through the lioebuck, Fallow-deer, Red-deer, to the Ox, where it 



constitutes the broad naked muzzle. 1 



The organ of smell in Carnivora mainly differs from that of 

 hoofed Herbivora in the greater relative size and strength of the 

 ethmoturbinal, the shorter, deeper, more massive and much more 

 subdivided ' maxilloturbinal.' In the Lion the ethmoturbinal is 

 of a pyramidal form, its broad base continued from the short 

 labyrinthic part attached to the cribriform plate, its apex termi- 

 nating forward, between the naso- and maxillo-turbinal. The 

 mesial surface of the ethmoturbinal shows numerous furrows, 

 two of which are longitudinal and parallel with the upper margin 

 of the bone, the others radiating from the lower part of the 

 attached base : the lateral or outer surface is less complex and 

 extensive ; but, on removing the outer layer, a series of con- 

 centric curved folds are exposed. The i nasoturbinal,' holding as 

 in Ungulates the highest position, is an elongate cone, co- 

 extensive with the roof of the nasal cavity and with its base 

 opposite to the frontal sinus : the mesial surface shows a series 

 of deep arched folds ; the lateral one seems more even, but when 

 the peripheral lamella is removed a series of longitudinal folds of 

 the bone is brought into view, beneath which are concentric folds 

 arched or curved in the opposite direction to those in the ethmo- 

 turbinal. The maxilloturbinal is fusiform ; the hind end is at- 

 tached to the outer wall of the nasal chamber below the middle of 

 the nasoturbinal ; whence the bone rises and expands, crossing 

 the anterior end of the ethmoturbinal, and again diminishing to its 

 anterior and upper attachment behind the external bony nostril. 

 From its position, therefore, the odorous atoms, in inspiration, 

 must first impinge upon this bone, and the pituitary membrane 

 is thicker and more vascular than on the other turbinals. Its 

 mesial or septal surface presents one curved groove, parallel with 

 and near to the lower margin of the bone : the outer surface has 

 a like character. The more glandular part of the pituitary mem- 

 brane is at the fore part of the floor of the nasal chamber, not 

 occupying so deep a fossa as in Ungulates. 



The sources and distribution of the nervous supply corresponds 

 with that noted in the Giraffe : the septal branches of the olfac- 

 tory curve down toward the thickened base of the partition. In 

 the Dog, the longitudinal folds of the i labyrinth ' are about four, 

 fewer in number but larger than in the Sheep : the aethmoturbinal 

 is continued from the undermost and curves upward slightly to 



1 This was pointed out to me by the estimable and justly famed water-colour 

 artist and animal painter, Robert Hills, F.L.S. 



