SPECIES AS TO VARIATION, ETC. 193 



somewhat similar views in Lis elaborate paper on 

 elephants, living and fossil, in the Natural History 

 Review for January last. Noting that " there is clear 

 evidence of the true mammoth having existed in 

 America long after the period of the northern drift, 

 when the surface of the country had settled down 

 into its present form, and also in Europe so late as to 

 have been a contemporary of the Irish elk, and on the 

 ather hand that it existed in England so far back as 

 before the deposition of the bowlder clay ; also that four 

 well-defined species of fossil elephant are known to 

 have existed in Europe ; that " a vast number of the 

 remains of three of these species have been exhumed 

 over a large area in Europe ; and, even in the geo- 

 logical sense, an enormous interval of time has elapsed 

 between the formation of the most ancient and the 

 most recent of these deposits, quite sufficient to test 

 the persistence of specific characters in an elephant," 

 he presents the question, " Do, then, the successive 

 elephants occurring in these strata show any signs 

 of a passage from the older form into the newer ? " 



To which the reply is : " If there is one fact which 

 is impressed on the conviction of the observer with 

 more force than any other, it is the persistence and 

 uniformity of the characters of the molar teeth in the 

 earliest known mammoth and his most modern suc- 

 cessor. . . . Assuming the observation to be correct, 

 what strong proof does it not afford of the persistence 

 and constancy, throughout vast intervals of time, of 

 the distinctive characters of those organs which are 

 most concerned in the existence and habits of the 

 species ? If we cast a glance back on the long vista 



