Dec, 1846.] 137 



This organ, from its situation, relative size to the degree of 

 perfection of the olfactive sense, as in the carnivorous Glandina 

 truncata, &c, its structure, and nervous supply, I think, is the ol- 

 factory organ.* 



The Committee on Mr. Cassin's communication, read Nov. 

 17, 1846, reported in favor of publication. 



Note on an Instinct probably possessed by the Herons, (Ardea, Linn.) 



By John Cassin. 



Several years since, I had an opportunity of observing the 

 Great Heron (Ardea Herodias, Linn.) engaged in capturing fishes, 

 and was much surprised at the singular facility with which he 

 struck his prey beneath the surface of the water. This was done 

 almost invariably by striking laterally and obliquely, very rarely 

 vertically or nearly so, as fishes came within reach. 



It appeared to me at that time, and more recent observations 

 have tended to confirm the impression, that this bird, and others 

 which procure food in the same manner, must possess an instinc- 

 tive knowledge of refraction. 



A moment's consideration is sufficient to warrant the inference 

 that this knowledge, if possessed at all, must be instinctive and 

 transmitted from parent to offspring; for it is obvious that if 

 every young bird should be obliged to acquire it, his risk of starv- 

 ing during such apprenticeship would be imminent. 



My observations have not been sufficiently extended to fully 

 justify a conclusion, but I have little doubt that the opinion here 

 expressed is correct, my object, however, is more especially to 

 ask attention to this remarkable and hitherto unnoticed subject. 



The Monthly Report of the Corresponding Secretary was 

 read and adopted. 



The Annual Report of the Treasurer was read and refer- 

 red to the Auditors. 



The Annual Report of the Librarian was read and adopted. 



* Since writing the above, I have had an opportunity, through 

 the kindness of Mr. Cassin, of examining a specimen of Helix poma- 

 tia, from Europe, in which I find the organ in question existing as a fun- 

 nel-shape depression beneath the mouth, and extending backwards along 

 the podal disk for the distance of three- fourths of an inch. This 1 con- 

 sider particularly interesting, as thesame species has been minutely dis- 

 sected and described by Swammerdam, Cuvier, and others, without anv 

 reference whatever to this cul-de-sac. 



