542 ME. H. M. KYLE ON NASAL 



In order to obviate a confusion of terms wliich miglit readily 

 arise in dealing with the subject of this paper, I shall refer to 

 the organ of smell as the olfactory organ ; to certain accessory 

 derivatives of that organ as nasal sacs ; to the one or two external 

 apertures of the olfactory organ of the Teleostei as anterior and 

 posterior nostrils ; and to the apertures and passages of com- 

 munication between the nose and the mouth as the posterior or 

 internal nares. 



The existence of nasal sacs in connection with the olfactory 

 organs of Teleostei has been noted by Owen, who in ' The Anatomy 

 of Vertebrates ' (p. 329) mentions their occurrence in the Mack- 

 erel {Scomber scomhrus L.) and in the Wolf-fish {AnarrhicJias 

 lupus, L.). In the latter he states that the " reservoir passes 

 backward (expanding) as far as the back part of the palate, 

 where it ends blindly : " and adds, " the prolongation of the single 

 nasal cavity in the Lamprey is analogous to this." Although 

 Owen* mentions the Mackerel as possessing these reservoirs, 

 they are comparatively slightly developed. JSolgerf has more 

 recently discovered a similar organ in the Stickleback. 



These are not the only species, however, where such " reser- 

 voirs " occur. They are met with in those forms which lead 

 a semi-sedentary life^ — in the Blenniidae, and (more largely 

 developed) in the Labridse and Scorpsenidse. Sometimes there 

 are two " sacs " in connection with each olfactory organ — 

 Scorpsenidae ; sometimes only one — Blenniidse and Labridse. 



These sacs are simple continuations of the nasal cavity and 

 possess no secretory function. They are " reservoirs " as Owen 

 called them, associated with the retaining, circulation, and 

 changing of the w^ater which passes through the nostrils. Their 

 walls are not muscular, and their capacity is determined merely 

 by the movements of the ascending processes of the premaxillae 

 and the maxillae and palatines. Solger suggests that they may 

 also furnish a habitat and breeding-place for Infusoria ! 



A further specialization of the nasal sacs is found in certain 

 groups of flat-fishes, and here also the number present for 

 each olfactory organ varies — in the Halibut, Plaice, and Turbot 



* Milne-Edwards also states that the nasal organ in the Mackerel possessed 

 a ' cul-de-sac' Le9. sur la Physiologie et I'Anat. Comp. torn, xi., 1877, p. 476. 



t Solger, B. : " Notiz iiber die Nebenhohle des Geruchsorgans von Gastrosteus 

 acukatus, L." Zeit. fur Wiss. Zool., Bd. 67, 1894, p. 186. 



