Proceedings of the Wcriurian Societij. 201 



1Sl14<, Feh.\'6. — Professor Jameson, P. in liie chair. — Dr T. 

 J. Aitkcn submitted to tlie considLration of the Society, a view 

 of the brain and cerebral nerves of the cod in general, and of 

 the olfactory nerve in particular, being part of the results of his 

 late physiological and anatomical investigations into the nervous 

 system of this animal. He shewed that the olfactory cavities 

 are comparatively small, though beautifully and elaborately con- 

 structed ; these cavities communicate externally by means of 

 two orifices, each furnished with a valve-like apparatus. The 

 surface is covered by a mucous membrane, elegantly plaited, and 

 defended by an abundant quantity of thick viscid mucus. 

 Pursuing the usual mode of tracing nerves from the brain, he 

 pointed out the olfactory connected with the inferior surface of 

 the anterior tubercles, from which they arise by two or three 

 capillary roots ; the two nerves soon unite and run together as 

 one nerve, along a canal leading from the skull forwards ; they 

 next enter a large oblong cavity, filled with a similar fluid to 

 that which occupies so considerable a part of the skull. Here 

 the nerve again divides into two, which diverge to their respec- 

 tive olfactory organs, on the central, internal, or convex surface 

 of which they are swollen into a ganglion, affording one of the 

 few examples of this modification of nervous structure in the or- 

 ganization of fishes. From the ganglion numerous threads are 

 seen passing to the membranes which penetrate it, and are dis- 

 persed freely upon it to receive the impressions of odorous ema- 

 nations. He obsc^rvcd, that though cod, when urged by the 

 cravings of hunger, swallow their food, apparently regardless of 

 its odour, and indeed occasionally voraciously devouring almost 

 every thing which comes in their way ; yet, on the other hand, 

 when surrounded by an abundance of their favourite subsist- 

 ence, as the herring, become extremely nice, and may be seen 

 to submit the bait to the sense of smell, and according to the 

 satisfaction afforded by the test, cither take it or turn av>'ay with 

 indifference or apparent contempt. After pointing out several 

 peculiarities in regard to the other nerves, Dr A. stated it as his 

 intention to submit to the Society further views in the same de- 

 partment on a future occasion. 



Dr John Coldstream then read a paper on the structure and 

 habits of the Limnoria terebrans, the small crustaceous animal 

 which has proved so destructive to the wooden erections on our 

 shores. (This interesting memoir will be found in No. 3^. of 

 this Journal, p. 316. et seq) 



1834, Mar. 15.— Dr II. K. Gukville, V. P. m the chair.— 

 Professor Jameson read a communication from Dr Meredith 

 Gairdncr, dated Fort Vancouver, 31st August 1833, containing 

 the details of the observations made by him during the voyag 



VOr.. XVITI. NO. XXXV. .T.WUARY 1835. () 



