CEPIIALOPODS. 323 



secretions of tlie other accessary organs to good digestion, 

 Sir E. Home believes that the inky fluid is intended also 

 to have some effect upon the lower portion of the intes- 

 tinal canal, to enable this to extract from its contents "a 

 secondary kind of nourishment,"* — an opinion not very 

 probable in itself, and witli but a few fanciful analogies iii 

 its support. 



* Comp. Anat. i. 369 and 393. 



*^* Troschel and, more iiarticularly, M. Loven, liave songlit in the form 

 and varions armatnre of tlic tongue of the Cei)lialopliorous mollusca (viz., 

 Ceplialopoda, Pteropoda, and Gasteropoda), a character on wliicli to distin- 

 guish their natural alliances and affinities. The researches of Lbvcn into 

 this subject seem to have been extensive, and are very intcrestino- ; but I 

 am only acquainted with them through the medium of an imperfect trans- 

 lation, witji the perusal of which I was favoured by Mr. Alder of Newcastle. 

 Hence, I cannot presume to offer the results, at which Loven has arrived to 

 the student. ' 



