118 
with Euchlaena “pollen. It “appears, 
therefore, ‘that the complete. resem- 
blance to the male parent, which we 
secured in the first’ cross; ~wasexcep- 
tional. Crosses. between Tripsacum 
and Zea, at least, usually show a com- 
plete resemblance to the female parent. 
It seems not improbable that the maize 
pollen served only to induce partheno- 
genesis in the Tripsacum parent. With 
the view of determining this point 
material for cytological study has been 
secured and is being investigated. 
CONCLUSIONS 
A cross between Tripsacum dacty- 
loides, female, and Euchlaena mexicana, 
male, has been carried through three 
generations without exhibiting any indi- 
cation of the characters of the female 
parent. In attempting to explain this 
complete absence of the characters of 
the female parent two alternatives may 
be considered. (1) The characters of 
the female parent have been completely 
masked by those of the male, or (2) the 
male nucleus developed in the ovary to 
the complete exclusion of the female, 
_.representing in a way the counterpart 
‘of parthenogenesis. 
The Journal of Heredity 
In the three genera- 
tions of the: progeny, of ‘this hybrid» at 
least 350 plants -hdve been examined. 
This and the fact that a great variety of 
conditions has called forth great varia- 
tion and induced many abnormalities 
without evoking any indication of 
Tripsacum characters has caused the 
first alternative to be dismissed. If 
the second alternative be adopted we 
are compelled to look upon the results - 
of this cross as a special type of inheri- 
tance not previously recognized. Hy- 
brids showing a predominance of the 
characters of the male parent have 
been described as patroclinous, but in 
this cross.and its successive progenies 
no trace of the characters of the female 
parent has been detected.’ No true 
hybridization or conjugation between 
the two nuclei appears to have taken 
place. For this form of false hybridi- 
zation the name patrogenesis is pro- 
posed. The term patrogenesis would 
also serve to place the phenomenon in 
proper contrast with parthenogenesis. 
This is rendered appropriate by the 
occurrence of what appears to be true 
parthenogenesis in Tripsacum, when 
pollinated with maize. 
The Effect of War 
WAR AND THE BREED, by David Starr Jordan. 
Pp. 265, price $1.35 net. Boston, The Beacon 
Press, 25 Beacon Street, 1915. 
Twenty years ago the idea that war 
was an important factor in changing the 
inborn nature of the human race was 
a novel one recognized by few. 
Jordan is largely responsible for making 
this fact seem almost a truism at the 
present day. In the present book he 
Dr.. 
has explained the thesis with a great 
wealth of illustration, and in a most 
readable way, prefacing the main dis- 
cussion with a short and popular out- 
line of the various methods in which 
evolution proceeds. The volume there- 
fore makes an interesting elementary 
treatise on eugenics, and one that from 
its timeliness ought to have a wide 
circle of readers. 
Reprints from the 
To contributors of articles describing 
the results of research, the American 
Genetic Association ‘will henceforth 
furnish, on réquest; «100 reprints with- 
out covers, gratis and post free. Addi- 
tional reprints can*be had at the fol- 
Jowing prices: 
Journal of Heredity 
50 copies, 4 pages...... $0.30 
50 copies, 8 pages...... oo 
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