94 The Journal 
leaflets. The two tip-layered plants 
in succeeding years continued to repro- 
duce themselves naturally by means oi 
suckers and tip-layers, and these also 
produced the divided leaflets of the 
original mutation. 
In the fall of 1919, two atavistic 
mutations were observed growing 
among the progeny of these plants. By 
careful study and root tracing, these 
atavistic forms were found associated 
only with those plants that had orig- 
inated as suckers from the roots of one 
of the original tip-layered plants, One 
of these atavistic mutations affects the 
four lower leaflets only, these being 
entire, while the upper leaflet is more 
or less divided (see Fig. 21). This 
form might be termed an intermediate 
type. The other mutation consists of a 
complete reversion of all the leaflets to 
the original undivided form. This is 
the extreme type (se Fig. 22). All of 
the leaflets on these later atavistic 
of Heredity 
plants are uniform, and none exhibit 
the tendency toward segmentation. 
From a horticultural viewpoint, these 
mutations are extremely interesting, 
and the finely divided leaf forms may 
even be termed ornamental. The canes 
normally grow arched, ascending about 
Z to 3 feet high with short, leafy 
flower clusters. The foliage on the 
young canes appears by far the more 
ornamental because of the beautifully 
five-pointed and much divided leaflets. 
On the fruiting canes the leaves are less 
divided and less graceful, and therefore 
such canes ought to be removed soon 
after the flowering season, Fruit on 
these mutating plants, especially the 
cut-leaved forms, is very seldom pro- 
duced, notwithstanding the abundance 
of pollen that is borne by the nine dif- 
ferent varieties of Rubus that grow in 
close proximity—in fact within the 
same row. 
HerepDITy AND ENVIRONMENT IN THE 
DEVELOPMENT OF MeN, by Edwin 
Grant Conklin, professor of biology 
in Princeton University. Princeton 
University Press, 1919. Third re- 
vised edition, Pp. 361, with 101 
illus, 
When Dr. Conklin’s book first ap- 
peared in 1914 it met with a warm wel- 
come, but much progress has been made 
since then in the study of eugenics, and 
an examination of this latest revision 
shows that the book has hardly been 
brought up to date. The principal 
changes have been made in the chapter 
on “The Cellular Basis of Heredity and 
Development,’ and Dr. Conklin’s 
authority in this field makes what he 
has to say on the subject welcome. 
But the sections devoted to eugenics are 
inadequate at present, and any serious 
discussion of the application of eugenics 
is almost lacking. The book is still dis- 
figured by a number of old illustrations 
that ought not to be allowed to circulate 
in the present age of photography, 
though their offense is more esthetic 
than scientific. 
The inadequacy of Dr, Conklin’s 
treatment of his subject is more or less 
inevitable, since he writes wholly as a 
biologist, and the study of heredity and 
environment of men from a purely 
biological point of view is fraught with 
great difficulties. A book on the sub- 
ject, to have much practical value, must 
be written largely from the biometric 
and sociological points of view. The 
author has perhaps made as much as 
possible out of the material available, 
but it will be a long while before the 
purely biological data available on man 
are sufficient to satisfy an inquisitive 
reader. Even of the material available, 
a more rigid selection should have been 
used, as in the enumeration of charac- 
ters in man that are supposed to be 
inherited in Mendelian fashion—P. P. 
