Hand and 
and easily kept, a series of prints being 
for most purposes more convenient for 
study than the actual objects; the prints, 
too, are more accurate records of the 
facts than any drawings or even photo- 
Foot Prints 
523 
graphs.” If genealogists would begin 
recording the finger prints of all the 
living individuals in their studies, a 
great deal of valuable material could 
be accumulated without difficulty. 
Mutations 
An oak-like mutation which occurred 
in the California black walnut and led 
some observers to suppose that a 
natural hybrid had been produced 
between oak and walnut, was described 
in this journal (VI, No. 12, December, 
1915) by Prof. E. B. Babcock of the 
University of California. He has now 
published further evidence that it is 
teally a mutant,;in UU. of C.. Pub. 
in Agric. Sciences, September 20, 1916 
(II, No. 3). Pollen from the oak-like 
mutant was applied to pistillate flowers 
in Walnuts 
of the California walnut; the resultant 
trees were all normal California walnuts. 
When this F,; generation was self- 
pollinated, twelve trees of Juglans 
californica were secured and six of the 
var. quercina. Prof. Babcock therefore 
thinks it likely that ‘“‘the genetic rela- 
tionship between californica and quercina 
is a difference in a single factor of the 
same Mendelian reaction system.” A 
parallel mutation has been discovered 
in the Northern California walnut 
(Juglans hindsit). 
Hereditary Nomadism and Delinquency 
The study of nomadism, recently 
initiated by C. B. Davenport (see the 
JOURNAL OF HeErReEpITY, April, 1916), is 
continued by J. Harold Williams in 
the Journal of Delinquency, I, 4, 209-233, 
September, 1916. Dr. Williams pub- 
lishes charts showing the family history 
of twenty-four nomadic delinquent boys, 
and also data about the families of 
twenty-four non-nomadic delinquents 
picked at random; and as there is more 
nomadism in the families of the nomadic 
boys than in those of the non-nomadic, 
he concludes that there is basis for the 
belief that nomadism (expressed often 
in the form of truancy in his cases) is an 
inherited trait. Aside from the diffi- 
culty of defining the trait, there is a 
lack of critical cases. There are doubt- 
less some hereditary factors back of 
nomadism, truancy, and ‘‘various kinds 
of periodic behavior,’’ but the studies so 
far made do not throw much light on the 
method of heredity. 
A Yellow Sweet Pea 
To produce a yellow sweet pea has 
been for years the ambition of sweet pea 
breeders, just as rose breeders have 
longed for a blue rose. The difficulty 
in each case is that the desired color 1S 
not found in the species, and the breeder 
is not able to secure it by combination 
with some other species. At the eighth 
annual meeting of the American Sweet 
Pea Society, David Burpee expressed 
doubt as to whether the yellow variety 
could be secured. If it does come, it 
probably will be as a result of crossing 
Lathyrus odoratus with some other 
species. Unfortunately, it does not 
cross. readily; in spite of the efforts of 
many breeders, it is said that no hybrid 
has ever been obtained between the 
sweet pea and any other species even 
of the same genus. 
