164 NATURAL SCIENCE [March 



The names in question, therefore, i.e., Post Tertiary, Quaternary, etc., 

 have a double frailty. Need I press my case in this behalf further. 

 I trow not, but, you will say, how can I presume to write in this 

 way when I have been guilty of .using this stupid nomenclature 

 myself. Of course I have been guilty of it. I have nevertheless 

 been ashamed of myself and am so still. My only excuse has been 

 that in order to be understood we must use the common shibboleths 

 of conversation, and in science these shibboleths are the technical 

 phrases of the text books. It does not make the boat less leaky and 

 unseaworthy because I happen to be in it along with the great guns 

 of geology, but I do try to make amends by professing my discon- 

 tent and shame. I challenge the authors of several recent text 

 books of repute to do the same. Let them justify, if they can, the 

 further use of such terms as Quaternary, Post Tertiary, or Eecent 

 (in the sense and with the connotation that Lyell used the word 

 recent). If they cannot justify them let us all agree to disuse them 

 as misleading and ridiculous and take a common stand on the plat- 

 form that we are all Tertiary Beasts, just as much as that stiff-necked 

 brute the Titanotherium, and tliat the Tertiary period comes right 

 up to to-day. 



Let us now turn to Ly ell's division and classification of the 

 Tertiary period. Lyell not only took over Deshayes' main divisions 

 of the Tertiary beds, but he also took over the former's general 

 criterion by which they were to be discriminated. This in 

 essence did not depend upon stratigraphical considerations or upon 

 natural breaks in the sequence, either by unconformability or other- 

 wise, such as we accept as our criteria in the older rocks, but upon 

 entirely different considerations, namely, the numerical proportion 

 of extinct to living forms in any particular bed. 



It must be also remembered that in Deshayes' scheme and also 

 in Lyell's the classification proposed was entirely based on the pro- 

 portion of extinct to living marine tcstacea only, and had applica- 

 tion therefore to marine beds only and had no reference of any kind 

 to the fauna of the land. 



Deshayes' method was called in (juestion when it was first 

 published both in England and in France, inter alia, by Bakewell 

 and Desnoyers, as being based on utterly arbitrary, uncertain, and 

 shifting data. Who is to know until the ocean bed has been 

 scoured from end to end what species are still living ? Every fresh 

 dredging expedition on a considerable scale adds to the number 

 of molluscs once supposed to be extinct and which are found to be 

 still alive, many of them (as in fact many of the fossil molluscs also) 

 having very local and limited distribution. 



The problem was further sophisticated by the fact that some of 

 the beds point to conditions of deposition similar to those in the 



