176 ESSAY ON CLASSIFICATION 



the type; it continues to exist while its representatives die, genera- 

 tion after generation. But these representatives do not simply repre- 

 sent what is specific in the individual, they exhibit and reproduce 

 in the same manner, generation after generation, all that is generic 

 in them, all that characterizes the family, the order, the class, the 

 branch, with the same fulness, the same constancy, the same precision. 

 Species then exist in nature in the same manner as any other groups, 

 they are quite as ideal in their mode of existence as genera, families, 

 etc., or quite as real. But individuals truly exist in a different way; 

 no one of them exhibits at one time all the characteristics of the 

 species, even though it be hermaphrodite, neither do any two repre- 

 sent it, even though the species be not polymorphous, for individ- 

 uals have a growth, a youth, a mature age, an old age, and are bound 

 to some limited home during their lifetime. It is true species are also 

 limited in their existence; but for our purpose we can consider these 

 limits as boundless, inasmuch as we have no means of fixing their 

 duration, either for the past geological ages, or for the present period, 

 whilst the short cycles of the life of individuals are easily measurable 

 quantities. Now as truly as individuals, while they exist, represent 

 their species for the time being and do not constitute them, so truly 

 do these same individuals represent at the same time their genus, 

 their family, their order, their class, and their type, the characters 

 of which they bear as indelibly as those of the species. 



As representatives of Species individual animals bear the closest 

 relations to one another; they exhibit definite relations also to the 

 surrounding elements, and their existence is limited within a definite 

 period. 



As representatives of Genera these same individuals have a definite 

 and specific ultimate structure, identical with that of the representa- 

 tives of other species. 



As representatives of Families these same individuals have a defi- 

 nite figure exhibiting, with similar forms of other genera, or for 

 themselves, if the family contains but one genus, a distinct specific 

 pattern. 



As representatives of Orders these same individuals stand in a def- 

 inite rank when compared to the representatives of other families. 



As representatives of Classes these same individuals exhibit the 



