LOBSTERS. 81 



Just as the lobster and the other higher forms of Crustacea 

 are characterised by having the 21 somites, so too they are 

 characterised by the fact that each appendage to those 

 segments is seven- jointed ; as will be easily seen by looking 

 at the walking foot (one of the small legs) of a lobster. 

 Now and again animals are met with, where the joints 

 so called are no longer joints in fact, but have become 

 fused together by long years of disuse. Nevertheless 

 the positions and forms of the joints are distinctly 

 visible. 



So far as I have been able to gather all scientists have 

 assigned to lobsters the senses of feeling, sight, hearing, and 

 taste. Most scientists, too, attribute them the sense of smell, 

 but Milne-Edwards, in " Todd's Cyclopaedia of Anatomy," 

 whilst admitting one cannot but believe, lobsters have well- 

 developed organs of smell, says it would be a mere conjecture 

 if one were to point out what one considered to be the precise 

 seat of those organs. Their sense of sight, however, is very 

 keen, and is claimed to be " equal to the most sharp-sighted 

 insect or the most agile of lizards." 



From the fact that they ordinarily select their food, one 

 would think that lobsters have both the sense of smell and of 

 taste, but, in any case, they have no tongue, although this is 

 doubtless compensated for by the fact that the interior of 

 the mouth and oesophagus is lined with a tegumentary mem- 

 brane. When feeding, lobsters hold their food in the larger 

 of the two claws or chelae ; it is then seized by the front feet, 

 passed on to the maxillipeds, and, by those organs, is separated 

 and passed on to the mandibles ; by these the food is further 

 sub-divided and then swallowed. The mouth proper consists 

 of a centrally-situated projecting upper lip, and a bifid lower 

 lip behind the projection of the upper lip. 



The respiratory organs of the lobster are bronchial (gills) 

 and pryamidal in form, eleven being on either side of the 

 carapace, opening externally, of course, and suitably protected 

 from injury. It is obvious, too, that opening externally as 

 they do, means must be taken to prevent the entrance of the 



