PHYSIOLOGY OP OLFACTION. 169 



wanting in the infant, which, notwithstanding, appreciates odours; 

 that they exist only in the mammalia; and that experiments would 

 seem to show, that the upper part of the olfactory organ is more parti- 

 cularly destined for the function, and that the sinuses, which, as well 

 as the membrane covering the middle and lower spongy bones, are 

 supplied by filaments from the fifth pair of nerves, are not sensible to 

 odours. 



Messrs. Todd and Bowman 1 from the fact, that on the septum narium 

 and turbinated bones bounding the direct passage from the nostrils to 

 the throat, the lining membrane is rendered thick and spongy by the 

 presence of ample and capacious submucous plexuses of both arteries 

 and veins, of which the latter are by far the larger and more tortuous 

 surmise, and Dr. Carpenter 2 thinks, with much probability, that the chief 

 use of these may be to impart warmth to the air, before it enters the pro- 

 per olfactive portion of the cavity ; as well as to afford a copious supply 

 of moisture, which maybe exhaled by the abundant glandulae seated in the 

 membrane. "The remarkable complexity of the lower turbinated bones 

 in animals with active scent, without any ascertained distribution of the 

 olfactory nerves upon them, has" they remark "given countenance to 

 the supposition, that the fifth pair may possess some olfactory endowment, 

 and seems not to have been explained by those who rejected that idea. 

 If considered as accessory to the perfection of the sense in the way above 

 alluded to, this striking arrangement will be found consistent with the 

 view, which thus limits the power of smell to the first pair of nerves." 



That the upper part of the nasal fossae is the great seat of smell is 

 proved by the facts referred to regarding the uses of the nose. Dessault 

 mentions the case of a young female, who had a fistula in the frontal 

 sinuses, and who could not perceive an odorous substance, when pre- 

 sented at the orifice of the fistula, because there was no communication 

 with the proper portion of the nasal fossae, although she was capable of 

 breathing through the opening. M. Deschamps, the younger, relates 

 the case of a man, who had a fistula of the frontal sinus, through which 

 ether might be injected without its odour being appreciated, provided 

 all communication had been previously cut off between the sinus and 

 the upper part of the nasal fossae; but if this precaution had not been 

 taken, the sense was more vivid, when the odours passed through the 

 fistulous opening, than when they reached the organ by the ordinary 

 channel. Again; M. Kicherand 3 found that highly odoriferous injec- 

 tions, thrown through a fistulous opening in the maxillary sinus or 

 antrum of Highmore, produced no olfactory sensation whatever. 



All these facts would seem to lead to the belief, that the upper part of 

 the nasal fossae, on which the first pair or olfactory nerves are distribu- 

 ted, is the chief seat of olfaction, and that the inferior portions of these 

 fossae, as well as the different sinuses communicating with them, are not 

 primarily concerned in the function: but, doubtless, offer secondary 

 advantages of no little importance. This conclusion, would, however, 

 seem to admit, what is not by any means universally admitted, that the 



1 Physiological Anatomy and Physiology of Man, ii. 3. 



2 Art. Smell, Cyclop, of Anat. and Physiol., Pt. xxxvi. p. 694, Lond., June, ] 849, 



3 Elemens de Physiologic, <klit. 13eme par Berard, p. 202, Bruxelles, 1837. 



