Recent Work on CEnothera. 
2 11 
Davis shows that about this time grandiflora was cultivated in 
England by Thompson, of Ipswich ; the evidence being a single 
sheet in Dr. Asa Gray’s herbarium at Harvard. It will be of great 
interest if any connection is established between grandiflora and 
Messrs. Carter & Co. at that period. 
J. A. Honing 1 has compared by means of careful measurements 
the “ twin hybrids ” Iceta and velutina (produced in F 1 of the crosses 
biennis 2 X Lamarckiana $ and biennis ? x rubrinervis g ) with 
Lamarckiana and rubrinervis respectively. His researches show 
that the Iceta hybrid has preponderating Lamarckiana characters, 
the velutina hybrid preponderating rubrinervis characters. The 
conclusion is drawn that the plants of these species are “flouble 
individuals,” the Lamarckiana having rubrinervis characters latent, 
the rubrinervis having Lamarckiana characters latent: these latent 
characters being revealed in crosses with biennis (or muricata). The 
theory is difficult to understand in that it is not elucidated by any 
scheme of a Mendelian nature : when the author says that by 
“double individuals” he means what others mean by the word 
“ hybrid ” it seems that he is straining the normal use of the word. 
The study, however, is of much interest in relation to other work 
on the possible hybrid origin of the Lamarckiana group of forms, 
and on the differing genetic content of pollen grains and ovules. 
H. H. Zeijlstra 2 has shown that the w r ell-known dwarf species 
described by de Vries and others as nanella, contains in local 
patches of the stem, and especially in the secondary wood, dark 
masses of a substance, which he interprets as the zoogloese of a 
species of Micrococcus: these sometimes cover as much as one- 
eighth the area of a transverse-section. To the presence of this 
supposed parasite is attributed certain features, hitherto regarded 
as typical of nanella, and giving it a diseased appearance— viz. the 
distortion of the leaves, the crookedness, imperfect unfolding and 
more or less marked sterility of the flowers. Rigorous proof, 
however, is not given for this statement; for not only is the 
identification of Micrococcus not critical (at least as described), 
but inoculation experiments were not performed, and artificial 
cultures of the organism are not mentioned; nor is information 
given as to the presence or absence of the dark masses in other 
species of Oenothera. “ Normal ” dwarfs occasionally arise, these 
differing from Lamarckiana chiefly in size: and “diseased” plants 
sometimes produce “ normal ” branches. The “ diseased ” 
condition is well-known to be transmitted to the offspring both by 
ovules and pollen-grains. 
R.H.C. 
1 “Die Doppelnatur der CE. Lamarckiana." Zeits. f. Ind. Abst.-u. 
Vererbungslehre, IV., p. 227, 1911. 
2 “ CEnothera nanella de Vries, eine krankhafte Pflanzenart.” Biol. 
Centalbl. XXXI., p. 129, 1911. Also Proc. Roy. Acad, of Sci., 
Amsterdam, Dec. 24th, 1910, p. 680. 
