TRANSMUTABLE. 39 



the same biography, with all its distinctive pe- 

 culiarities.' ' (Reprinted from the Journal of the 

 Philadelphia Academy of Natural Science, in 

 Stainton's Entomological Annual for 1860. 



And what says Professor Owen, a man whose 

 authority, I presume, no one will doubt: u No 

 species of animal has been subject to such decisive 

 experiments, continued through so many genera- 

 tions, as to the influence of different degrees of 

 exercise of the muscular system, difference in 

 regard to food, association with man, and the 

 concomitant stimulus to the development of in- 

 telligence, as the dog; and no domestic animal 

 manifests so great a range of variety, in regard, 

 to general size, to the colour and character of 

 the hair, and to the form of the head, as it is 

 affected by different proportions of the cranium 

 and face, and by the intermuscular crests super- 

 added to the cranial parieties. Yet under the 

 extremest mark of variety so superinduced, the 

 naturalist detects in the dental formula, and in 

 the construction of the cranium, the unmistakable 

 generic and specific characters of the Canis 

 familiaris" (On the Classification and Distri- 

 bution of the Mammalia, 1859.) 



What says Mr. Woollaston, who is so often 

 ([noted by Mr. Darwin, and who is undoubtedly 

 one of our best writers on the variation of 

 species: u However difficult it may be in some 

 instances to distinguish aright between species 

 and varieties as rigidly defined, there is an instinct 

 within us which often recognises the latter, even 



