1898] SOME NEW BOOKS LY 
who desires to comprehend something of the work now being done on 
variation, on selection, on specific differentiae, and so forth, or “who may 
even be bold enough to attempt some of these mathematical methods 
himself, Mr Lupton’s book will come as a godsend. The chapters on 
Ideas, on Reasoning, on Fallacies, on Laws of Nature, on Cause and 
Effect, and on Observations and Experiments, with their references to 
larger works, may be read with profit by many who think they were 
taught all about such things at school. But it is when we get to the 
explanation of such things ¢ as Units and Dimensions, Averages, Differ- 
ences, Mensuration, the Use of Tables, Errors, Means, the Law of Error, 
and Graphical Methods, that the special value of Mr Lupton’s book 
becomes apparent. There are many who will be glad to learn the 
difference between an Average and a Mean, and more particularly to 
know which of the various Means is the one now selected by mathe- 
maticians as the Mean, while the difference between the Mean and the 
Mode is another subject upon which light is needed by a good many 
who are not so well acquainted with Prof. Karl Pearson’s writings as 
they ought to be. 
Nevertheless, valuable though Mr Lupton’s book is, we should 
greatly like to see a manual on the same lines, but more especially 
adapted for the biologist. Nearly all Mr Lupton’s are taken, as is 
natural, from physics or chemistry; Prof. Weldon and his crabs are not 
so much as alluded to. But the construction of graphical curves to 
represent biological observations presents difficulties and complications 
of its own. The useful application of logarithmically ruled section- 
paper was recently suggested by Mr D. J. Scourfield ; while readers 
who are interested in the determination of species will find an inter- 
esting application of mathematical methods suggested by Prof. C. B. 
Davenport in Science for May 20. We merely mention these papers 
as examples of the kind of thing that might well be incorporated in a 
text-book of biological mathematics, and we can but regret that so use- 
ful a person as Mr Lupton has been lost to our own branch of science. 
HISTORICAL SPECIMENS OF FossIL CEPHALOPODA 
List OF THE TYPES AND FIGURED SPECIMENS OF FossIL CEPHALOPODA IN THE 
British Museum (Natural History). By G.C. Crick. 8vo, boards, pp. vit+ 104. 
London. 1898. Price, 2s. 6d. 
To the serious worker who is called upon to identify organisms nothing 
is more helpful, and in critical cases essential, than a comparison with 
the specimen on which the original description was based ; and to 
such persons there is no more welcome aid than a directory of these 
so-called type-specimens. As regards the British fossils, a Committee 
of the British Association has long been collecting information with a 
view to such a list, and owing to its exertions several museums (among 
others, those of Cambridge, Manchester, and York) have printed and 
published lists of their type fossils. 
The present catalogue enumerates somewhere about 1000 speci- 
mens (a striking illustration of the wealth of the British Museum) 
with full references to the places where they have been described and 
figured, as well as to their locality and stratigraphical horizon. 
They are arranged alphabetically according to the generic names 
K 
