1908.] 



ON OLFACTORY ORGANS OF FISHES AND BIRDS. 



65 



that were rarely imported alive to Europe, so that a correct idea 

 of their true form might be conveyed to artists and taxidermists. 

 In the present instance the value and interest of the photograph 

 submitted to the Society by Mr. Cross might be judged by com- 

 paring it with the stuffed specimens of this Dog exhibited in 

 mviseums and with the published lithographic figures of the 

 species. 



Mr. R. H. Burne, F.Z.S., exhibited a pi-eparation * of the head 

 of a Sea-Lamprey {Petromyzon marinus), designed to show the 

 mechanism by which water is drawn into the olfactory chamber 

 at each inspiration and expelled at each expii-ation. The current 

 of water is produced by the alternate compression and expansion 

 of the blind bulb-like end of the nasal sac. This sac is separated 

 from the branchial chamber by the thin compressible oesophagus 

 only and responds to the alterations in pressure within the 

 branchial chamber that are due to the alternate expansion and 

 contraction of its walls during the process of respiration. The 

 current of water entering the nostril is deflected by valves into 

 the olfactory chamber and among the leaves of the olfactory 

 rosette before passing into the nasal sac. 



Text-fio-. 16. 



OL.E. 



OL.B. 



Section of the head of an Albatross {Diomedea exulans). 



L.D., opening of laciymal duct ; M.T., maxillo-turbinal ; N.D., opening of duct 

 of nasal gland ; OL.B., olfactory bulb ; OL.E., olfactory eminence. 



The action of this mechanism has been observed and recorded 

 by Bert (Ann. Sci. Nat. ser. 5, t. vii. 1867, p. 372.) 



* No. E 85, Physiol. Series, K. College of Surgeons' Museum. 



Proc. Zool. Soc— 1 908, No. V. 5 



