3oo 
22. Giglio-Tos, E. 
R. Ruggles Gates. 
“ Les dernieres experiences du Prof. De Vries et 
l’eclatante confirmation de mes lois rationelles de 
l’hybridisme.” Biol. Centralbl., Bd. 31, 1911, pp. 
417-425. 
23. Goldschmidt, R. “ Die Merogonie der CEnothera- Bastarde und die doppel- 
treziproken Bastarde von De Vries.” Arch. f. 
Zellforsch., Bd. 9, 1912, pp. 331-344, 6 figs. 
24. Heribert-Nilsson. N. “ Die variabilitat der CEnothera Lamarckiana und das 
Problem der Mutation.” Zeitschr. f. Abst.— u. 
Vererbungslehre, Bd. 8, 1912, pp. 89-231, 3 plates, 36 
figs. 
25. Honing, J. A. “ Die Doppelnatur der CEnothera Lamarckiana." Zeitschr. 
f. Abst.-u. Vererbungslehre, Bd. 4, 1911, pp. 227- 
278, 10 figs. 
26. Reveille, H. “ Monographic du genre Onothera. III.” Le Mans, 1913. 
27. Lutz, Anne M. “ Triploid mutants in CEnothera." Biol. Centralbl., Bd. 
32, 1912, pp. 385-435, 7 figs. 
28. Stomps, T. J. “ Die Entstehung von CEnothera gigas De Vries.” Ber. d. 
deutsch. bot. Ges., Bd. 30, 1912, pp. 406-416. 
29. ,, “Mutation bei CEnothera biennis L.” Biol. Centralbl., 
Bd. 32, 1912, pp. 521-535, pi. 1, fig. 1. 
30. Strasburger, E. “ Chromosomenzahl.” Flora, Bd. 100, 1910, pp. 398- 
446, pi. 6. 
POSTSCRIPT. 
Since this very condensed review was written, an important 
work by De Vries 1 has appeared, dealing chiefly with CEnothera 
experiments and considering the whole mass of results in relation 
to the mutation theory. An impression of its comprehensive 
treatment of the subject of heredity and mutation in CEnothera may 
be obtained from the headings into which the work is divided. These 
are (i.) the origin of species through mutation, (ii.) reciprocal and 
double reciprocal hybrids, (iii.) twin hybrids, (iv.) the pangenetic 
investigation of new species, (v.) the causes of mutations. Many 
of the results here presented in extenso have been published in 
summary form during the last few years. 
The great value of the present book lies not only in the huge 
accumulation of experimental data which it contains—and this is 
far more extensive than has ever been brought together for any 
other similar group of forms—but in the remarkable manner in 
which the hereditary behaviour and the mutation behaviour are 
shown to be correlated. The analysis of various wild species, such 
as O. biennis L., O. mnricata L., O. Hookeri Torr. and Gray, 0. 
cruciata Nutt., O. strigosa Rydb., and several undescribed species, 
is carried out by means of extensive series of crosses. These are 
the reciprocal and double reciprocal hybrids. For the most part 
the reciprocal hybrids are unlike, being usually patroclinous. In 
this way it is shown that the pollen and egg-cells of various species 
are carrying different qualities, those of the pollen being usually 
nearly the same as the external characters of the plant, while 
those carried by the eggs are quite different and can only be brought 
to light by crossing with certain species whose pollen and egg-cells 
carry the same characters. 
' De Vries, Hugo. “ Gruppenweise Artbildung, unter specieller Beriick- 
sichtigung der Gattung CEnothera." GebrLider Borntraeger, Berlin, 1913; pp. 
365, with 22 coloured plates and 121 text-figures. 
