CRUSTACEANS. 139 



CHAPTER III. 



CRUSTACEANS. 



It is the common infirmity of Naturalists, and indeed of all syste- 

 matic authors attempting general classification, to comprehend every 

 subject -within its bounds, which shall be sanctioned even by implication. 



Hence, unless for judgment and discrimination, a miscellaneous 

 mass accumulates, which, along with pertinent matter, includes much 

 which might be assigned to another more convenient position. 



It is now that subdivision resting on analogy becomes essential, so 

 tha,t, with the immoderate multiplication of genera, and the unreason- 

 able separation of kindred species, those products of reciprocal resem- 

 blance yet exhibiting sensible distinctions, may be approximated. 



But the arrangements must be adjusted according to the facts oIj- 

 tained from repeated correct observation in the wide expanded field of 

 Nature. 



The cultivators of science having multiplied of recent years, and 

 each being prone to take a different view from his fellow labourers, it is 

 the principal office of the experienced practical observer to preserve an 

 accurate and veracious record of such facts as may have fallen under 

 notice in his own department. 



, The precise mode of study is scarcel}^ to be prescribed ; it must be 

 regulated by discretion, recollecting, however, that the more pi-ominent 

 features of animals are the better guides, that examples should be dis- 

 tinct and numerous, so that illustrations may be readily found among 



