CEREBRAL DEVELOPMENT OF BIRDS. 87 



figuration of the cranium, and consequently of the whole 

 body, is nearly similar. Besides, Vimont, when it suits his 

 purpose, does not hesitate to compare birds widely sepa- 

 rated from each other,* although he himself at another time,f 

 insists on the necessity of their belonging to the same family, 

 or even genus, in order to render them legitimate objects 

 of phrenological comparison ; and if Vimont follows this 

 double mode of inquiry, why should not also his opponents 

 be entitled to use the same weapons as himself? 



That extraordinary impulse, or instinct, which impels 

 certain birds to migrate at definite periods, though at all 

 times the wonder of naturalists and philosophers, as fur- 

 nishing an ample field of interesting inquiry, still remains 

 as mysterious as ever. How a little bird like the swallow, 

 should come from some unknown region of the " sunny 

 south," a distance of thousands of miles, and, with unde- 

 viating accuracy, return to the land which gave it birth, 

 nay, even the very spot where it was hatched the preced- 

 ing year, and perform all this migration anew during every 

 succeeding year of its existence, has ever been reckoned 

 one of the mysteries of nature. 



Phrenology professes to account for the migration of birds 

 on rational principles ; for Dr. Gall traced it to a periodical 

 excitement of the organ of Locality, which he maintains is 

 very large in all migratory birds. Vimont even professes 

 to be able to point out, a priori, a migratory from a resident 

 bird, by the configuration of its cranium ; and he tells us 



f Traite de Phrenologie, p. 304, where he compares the skull of a 

 hen with that of a buzzard, birds as widely separated as possible, 

 t Ibid. p. 261. 



