168 NATURAL SCIENCE [March 



me every subsequent inquirer into this particular corner of the 

 geological field has fallen. The only escape from it is either to 

 drop the term as applied to the English beds altogether, and to let it 

 stand (if thought riglit) for the ^Mediterranean beds alone, or to try 

 in some way to entirely alter the definition and connotation of the 

 term from what it originally meant, and from what its author and 

 inventor meant. This seems very much to me like referring to some 

 dull, sober, quiet, ortliodox geologist by the name of Howorth. I 

 cannot put the rcductio ad. ahsurdum more thoroughly. 



Let us, however, advance again. Lyell in taking over Deshayes' 

 division of the Tertiary beds altered it in one respect. He divided 

 it into four series instead of three, and in my view altered the 

 French writer's classification very much for the worse. " He altered 

 it by, in fact, separating the uppermost division which had been 

 discriminated by Desliayes into two divisions, to which he gave the 

 name of older and newer Pliocene respectively. This would have 

 been acceptable and useful if applied to the Mediterranean series of 

 Deshayes alone, and if it had been understood that it merely meant 

 the breaking up of one of Deshayes' main divisions into two subordinate 

 ones, but this is not at all what Lyell meant. In his scheme each of 

 the two divisions of the Pliocene series is itself given co-ordinate rank 

 with the other two great divisions of the Tertiary beds, namely, the 

 Eocene and Miocene (see his table Principles of Geology, ed. ii., vol. 

 iii., p. 61), and he emphasised this very strongly in the French 

 translation of the Princiiyles by introducing for the first time the 

 term Pleistocene, which he made the equivalent of his " later 

 Pliocene." Subsequently he dropped the two divisions of the 

 Pliocene and divided the whole Tertiary series into four great 

 sections, namely, the Eocene, Miocene, Pliocene, and Pleistocene. 



Here again, it seems to me, we have another instance of an entiie 

 absence of proportion and of perspective in Lyell's method of 

 classification. 



The differences which separate Eocene from Miocene life are 

 assuredly patent enough, and they involve real and substantial 

 biological and other differences. The same is the case when we 

 distinguish Ijetween the beds classed as Miocene and those classed 

 as Pliocene ; but what sort of differences at all comparable to these 

 separate the Pliocene from the Pleistocene. Even if we limit our- 

 selves to Italy and its marine beds, they are so slight that Deshayes 

 condensed them both into one series ; but as applied elsewhere by 

 Lyell, namely, to the countries of the North Sea, they are, with our 

 present knowledge, positively ridiculous. They were always quite 

 inadequate, however, and at the very most justified the creating of 

 subsections of the Pliocene just as we now have subsections of the 

 Miocene, but nothing more, and to introduce a new term like 



