162 THOUGHTS ON SPECIES. 



ceedecl from the admixture of several originally distinct spe- 

 cies. Whilst it is a doubtful question, no illustration can be 

 drawn from this source, and we must look for the determi- 

 nation of important questions from the internal evidence pre- 

 sented in the study of special orders, and, perhaps, especially 

 amongst the humble beings. Neither do I imagine anv light 

 can be derived from the action of physical influences on the 

 vegetable organism, however similar may be the nature of 

 the vegetative process in the two organic kingdoms; for the 

 very condition of life in the one is absolutely dependent on 

 them, not only for its inception, but for its subsequent conti- 

 nuance ; whilst the other is in nowise thus circumstanced 

 within the limits of variations not actually and immediately 

 destructive. Surely the consideration of the nature of spe- 

 cies and varieties is important, obscure and difficult enough 

 without being further complicated and confused by brilliantly- 

 conceived theories, when facts should be sought for, or by 

 mere postulatory reasoning founded on supposititious events. 

 The existence of modified individuals, under different cli- 

 matal conditions, is no proof in itself that the modifications 

 of structure or ornamentation are the consequence of the 

 operation of physical influences, particularly when we are 

 acquainted only with the perfect insect. Independently of 

 the consideration that they are constantly met with under all 

 climatal conditions, the idea of species includes certain esta- 

 blished and ordained relations to physical agencies, which, so 

 far from being adventitious in their operation, are part of 

 its history. And, with the original conception, must have 

 been likewise predetermined those products of disorder, that 

 harmonize completely with the dominant idea, although pre- 

 senting differences — the adaptability to certain modes of life, 

 the form and structure, the relations of species to its natural 



