No. 396.) REVIEWS OF RECENT LITERATURE. 975 
thousands of individuals. And this not only for one species but for 
a whole fauna, as: “A basis for an arbitrary distinction between 
Species and varieties may be gained by determining a degree of diver- 
gence and of isolation which shall be used to distinguish the two. 
A degree of divergence of thrice the standard deviation has been 
suggested as a convenient line between species and varieties.” The 
idea of such a broad application of the ‘“ newer statistical methods,” 
and for such purposes, seems at present Utopian, because simply 
impracticable. Again, an arbitrary standard of deviation which may 
be perfectly legitimate for one group, as a genus or family, would 
prove inapplicable for another group of similar grade within even 
the same class. 
As already said, the scheme is theoretically admirable, and is no 
doubt applicable to many special problems, but is too costly in time, 
material, and labor to be of the wide or general applicability in 
determining species and subspecies, or the methods and causes in 
the segregation of geographic forms, apparently contemplated by 
the author of the present manual. The gross methods already in 
vogue, being tolerably efficient for temporary and tentative purposes, 
will probably hold the field for a while at least, so that it will be in 
the remote future when, through the plotting of curves and the use 
of logarithmic tables, we shall see “by the use of the quantitative 
method biology . . . pass from the field of the speculative sciences 
to that of the exact sciences ” (p. 39). YAA 
The question of the former existence of an Antarctic continent 
with a flora and fauna of its own, the remnants of which are still 
recognizable in the southern continents, has been brought into prom- 
inence recently, and we should like, in this connection, to call atten- 
tion to a paper published in Australia that, although issued four 
years ago, has not been noticed sufficiently in other countries. 
C. Hedley? starts from the fact mentioned already by early travel- 
ers, that Tasmania, Australia, New Zealand, South America, and 
partly also South Africa contain certain forms of life in common 
which are not represented elsewhere, and concludes that this com- 
munity of type cannot be explained but by community of origin, and 
that we have to look for a connection of these now separated parts 
by former land bridges. 2 
After discussing and criticising the theory of Hutton, which con- 
1 Hedley, C. Considerations on the Surviving Refugees in Austral Lands of 
Ancient Antarctic Life, Roy. Soc. N. S. Wales. Aug. 7, 1895. 
