TRANSMUTABLE. 47 



invariability as the great planets observe in their 

 appointed paths." 



And to continue the chain of this beautiful 

 reasoning, let us hear what the same writer says 

 of a variety as distinct from species. 



"For wherein does a variety differ from species? 

 Is it by any difference in the ovum, any peculi- 

 arity in the form, structure, ornamentation, or 

 biography of the embryo, any difference in pu- 

 pation, or any essential or specific variation in 

 the structure of the perfect insect? By 110 means. 

 To be a variety or wandering from a certain 

 specific type, it must observe the same biographical 

 and organic cycle, possess the same specific cha- 

 racteristics of structure in its perfect state, but 

 differ from the species in its peculiarities of or- 

 namentation, and in its size perhaps, to a degree 

 that without a knowledge of its embryology and 

 biography it would be pronounced and registered 

 distinct from the perfect individuals, towards which 

 it shews the strongest specific affinities of struc- 

 ture. 



Variation or specific instability observes fixed 

 and determined limits, which must be ascertained 

 by observation in part of the true history of 

 species. It is not manifested to the same degree, 

 probably in the specific character of every true 

 species, but wheresoever and whensoever it does 

 occur is capable of being referred to its normal 

 type by its agreement in all those essential 

 characteristics necessary to form a conception of 

 a true species. As long as the diagnosis must 



