162 NATURAL SCIENCE [March 



of the Primary, Secondary and Tertiary periods. This separation 

 of the Recent beds was widely, almost universally, accepted ; and 

 presently — namely, in 1849 — a new name was given to them by 

 D'Archiac, namely, Quaternary, thus empliasizing the enormous im- 

 portance which they held in the eyes of a popular school of 

 Geology, since the very name Quaternary was merely the comple- 

 tion of the cycle of names already referred to — namely. Primary, 

 Secondary and Tertiary ; and this term Quaternary not only still 

 lives, but is in continuous use, and especially by the geologists of 

 the continent. 



Now, some of us know well, or think we know, the vast differ- 

 ence that separates the Primary, Secondary and Tertiary beds. The 

 huge gap which separates their fossil contents in our latitudes 

 makes it necessary to deal with them in any systematic scheme 

 of geology as ultimate and supreme factors. 



In order to create a fourth division co-ordinate with them, we 

 ought assuredly to have co-ordinate conditions separating the 

 Tertiary beds from the ' Recent ' beds of Lyell and the 

 Quaternary of other writers. Let us turn then to Lyell's own 

 words, and see how he defined his Recent beds, and by what 

 criteria he separated them from the beds he called Tertiary. 



I shall quote his own definition : " All sedimentary deposits, all 

 volcanic rocks — in a word, every geological monument, whether be- 

 longing to the animate or inanimate world, which appertains to 

 this epoch, may be termed recent. Some recent species, there- 

 fore, are found fossil in various Tertiary beds; and, on the other 

 hand, others, like the Dodo, may be extinct, for it is sufficient 

 that they should once have co-existed with man, to make them re- 

 ferable to this era." Again he says : " We may sometimes prove 

 that certain strata belong to the recent period by aid of liistorical 

 evidence, as parts of the delta of the Po, Rhone and Nile, for 

 example ; at other times, by discovering imbedded remains of man 

 or his works ; but when we have no evidence of this kind, and we 

 hesitate to ascribe a particular deposit to the recent era, or that 

 immediately preceding, we must generally incline to refer it to the 

 latter, for it will appear in the sequel that the changes of the his- 

 torical era are quite insignificant when contrasted with those of the 

 newest Tertiary period." 



Here then we have the ear-mark by which Lyell discriminated 

 his Recent or Post Tertiary beds, namely, the presence in them of man 

 and his works, and that alone. This may have been pardonable in 

 1830, but what is to be said of it now ? What is to be said for a 

 classification which is based professedly on biological evidence, and 

 which treats the introduction not of a very specialised mammal or 

 series of mammals differing essentially from their predecessors ? but 



