106 SPECIES NOT 



be reconciled upon the hypothesis of a common 

 origin for creatures destined to live for ever in 

 a dark cave, and not likely to "emigrate," or 

 get upon a "glacier." In fact I think Mr. 

 Murray's argument is unanswerable. 



The following is an extract from Mr. Murray's 

 paper, (Edinburgh New Philosophical Journal, 

 No. I.,, January, 1860, page 149:) "The most 

 striking fact, and the one which to my mind 

 disposes of the whole matter, is the existence of 

 species of the same genera of eyeless insects, ex- 

 isting in the vast subterranean isolated caves of 

 Carniola, allied, and exceedingly closely allied to 

 similar species in the caves of Hungary ; to similar 

 but different species in the caves of the Pyrenees ; 

 to similar but different species in the caves of 

 Auvergne; and more than all to similar but dif- 

 ferent species of the same genera in the mammoth 

 cave of Kentucky. Each of those set of caves 

 lias a different set of species of the same genera, 

 jii id all very closely allied. The physical condition 

 of the place being the same, the product has been 

 the same; but not by immigration, nor any means 

 of distribution which we can imagine. Can iden- 

 tical species, (for remember the theory implies that 

 congenerous species are identical, or, what is the 

 same thing, their descendants,) be found in caves 

 so widely separated; arid it is not the common 

 case of congenerous species found very wide apart, 

 which may yet have traversed the intervening 

 space, because these insects are found nowhere 

 but in caves, arid not in them until you have 



