36 SOME THOUGHTS ON CLASSIFICATION 



as we go down to lesser groups we find that the more minutely we 

 have studied their structure and their life history, the more readily 

 and confidently cati we associate the objects, by means of what is 

 common to them, setting aside objects which imitate them analogi- 

 cally or merely externally, but have no conformity in the points 

 which manifest real affinity. If, in addition to an acquaintance with 

 the varieties of external form and aspect in all organised beings, we 

 knew all the modifications of their internal structure with the exact 

 bearing of each on the performance of the vital functions, and the 

 wants and habits of the creature ; and if we farther had traced the 

 progress of each organism from its origin to the close of a life not 

 interrupted by accident or violence — supposing that we had compre- 

 hension of mind to embrace and duly apply this various knowledge, 

 our association of the objects according as their agreements and 

 differences related to points the most important and the most numer- 

 ous would produce a perfect natural system ot organised beings, 

 where the student in becoming acquainted with the classification, 

 would, at the same time, learn the real nature and condition of the 

 objects, and the generalisations set before us would enable us with 

 certainty to trace each object to its place in the system, whilst, at the 

 same time, conveying to us the best information respecting its struc- 

 ture, relations, and mode of existence. Physiological science combined 

 with observation of external appearance and habits of life, forms the 

 solid foundation for all good classification. Some good use has 

 already been made, and may further be made of the knowledge 

 already attained, but the road to improvement opening to us the 

 hope of better things in future is to be sought in the cautious inves- 

 tigation and faithful record of facts observed in the fields, woods, 

 and waters, or laid open by the dissector's knife or by the wonderful 

 power of the microscope. According to their genius, their prepara- 

 tion and their personal circumstances and habits, it belongs to some 

 men to collect together further materials ; to others to arrange and 

 •combine these, incorporating them with those previously accumulated 

 and making huch new distributions as increasing knowledge demands ; 

 but there is no lover of nature noting what he observes, who is not a 

 useful labourer in advancing that science whose crowning success 

 must be a good natural system, enabling us to view all organised 

 beings in their mutual relations, to derive from their contemplation 

 the greatest amount of pleasure and utility, and to catch at least some 



