62 Gen. Sub . 
I. GENERAL SUBJECTS. 
no such leap, the variation is, so to speak, a mere bend or divergence 
from the parent form, towards which the offspring in the next genera- 
tion will tend to regress ; it may, therefore, be termed a ‘ divergent ’ 
variation ” ; Galton (176). 
On variations and mutations, criticism of Bateson’s work : Palaeonto- 
logical evidence as to mutation, i.e ., steady advance along certain definite 
lines, as opposed to individual variation. “We can no longer assume as a 
fundamental and self-evident truth, that individual variations are the 
material from which new species are constructed” ; Scott (501). 
“ The succession of the various species does not represent an evolution 
by deviations merging insensibly into each other, but by successive stages, 
each a distinct departure, and as clearly separated from its predecessor 
and successor as one species from another ” (cf. Mr. Bateson’s thesis !) ; 
Anon. (11). 
“ The differentiation of every new species resulted from new forces ab 
extra superimposed on, aud, to some extent, superseding or modifying 
the forces that produced the species or genus immediately preceding in 
the same line of development; ” Anon. (11). 
Correlated variations in eleven parts of 1000 adult females of shore- 
crab. “The problem of animal evolution is essentially a statistical 
problem : before we can properly estimate the changes at present going 
on in a race or species we must know accurately (a) the percentage of 
auimals which exhibit a given amount of abnormality with regard to a 
particular character ; (b) the degree of abnormality of other organs 
which accompanies a given abnormality of one ; ( c ) the difference 
between the death-rate per cent, in animals of different degrees of 
abnormality with respect to any organ ; (<7) the abnormality o z offspring 
in terms of the abnormality of parents, and vice versa .” When we know 
the numerical answers to these questions for a number of species, we 
shall know the direction aud the rate of change in these species at the 
present day, a knowledge of which is the only legitimate basis for 
speculations as to their past history and future fate ; Weldon (566). 
Correlated variations of external parts in Palcemon serratus ; Thomp- 
son (533). 
Mathematical treatment of variations ; Pearson (409). 
In skull of Neotoma micropus there is “a wide range of purely 
individual variation, affecting every character that can be used in a 
diagnostic sense ” ; Allen (5). 
Variation of antlers : These fall into three chief groups, and the 
specimens form a fairly continuous series ; Fowler (167). 
Origin of structural variations ; Cope (100). 
Mechanical cause of folds in the aperture of Gasteropod shell ; Dall 
(109). 
Variations in Molluscs ; Sacco (479). — Variation in Mollusc shells : 
Due to relation of animal to shell and to environment; Mason (337). 
Causes of variations in bones of the foot ; Tornier (535, 536). 
Modification of Galton’s curves: Due to parasitism ; Giard (187). 
