MISCELLANEOUS. 



263 



likeness to that on which our ordinary ideas of such an 

 organ are to be founded. For, instead of being a pro- 

 jecting body, lying in the 

 cavity of the mouth, it is a 

 tube that passes backwards 

 and downwards beneath the 

 mouth, its hinder end being 

 closed, whilst in front it 

 opens obliquely upon the 

 floor of the mouth, being 

 (as it were) slit up and 

 spread out, so as to form a 

 nearly flat surface. . . . The 

 length of the tongue, and 

 the number of rows of teeth, 

 vary greatly in different 

 species. Generally speak- 

 ing, the tongue of the terrestrial Gasteropods " (that is, 

 such as land-snails) " is short, and is contained within the 

 nearly globular head ; but, the rows of teeth being closely 

 set together, they are very numerous, there being fre- 

 quently more than 100, and 

 in some species as many as 

 160 or 170, so that the total 

 number of teeth may mount 

 up, as in Helix pomatia, one 

 of the garden shell-snails, 

 to 21,000; and in Limax 

 maximus (the great spotted 



Palate of sea-sing (Don* tubercu* 

 lata). 



A portion of greatly magnified teeth 

 of the garden snail, separated to 

 show their form. 



slug) to 26,800." 



You would be wearied 

 with a description of the 



marvellous beauty of these palates or tongues when nicely 

 seen either by polarized light or the dark-ground illumi- 



