148 BOTANICAL GAZETTE [FEBRUARY 
the production of several more “graft hybrids” by the use of the same 
methods.s In this paper four varieties of graft hybrids are described, and are 
tomato, while the last two are closer to the tomato. Some of the new forms 
appeared more than once in the cultures, S. Gaertnerianum, for example, being 
observed to arise five times. Some of the new forms appeared as branches 
from chimeras. In a recent paper® WINKLER reports the results of a study 
of the progeny of the new forms. Although the vegetative shoots seem able 
to fuse and merge readily in various ways, the tomato and nightshade cannot 
be hybridized sexually. WINKLER observes that the “graft hybrids” without 
exception revert to the nearer parent, the seedlings of Solanum tubingense, 
. Darwinianum, and S. Gaertnerianum always being S. nigrum, while the 
seedlings of S. proteus and S. Koelreuterianum always are S. Lycopersicum. 
e new forms may be hybridized sexually with the nearest parent form, the 
progeny being pure nightshade or tomato, as the case may be. Furthermore, 
reversion in the vegetative shoots is to the nearer parent form. 
While WINKLER’s results are accepted without debate, his interpretation 
has been called in question by various investigators. It may be noted that the 
behavior of the new Solanum forms is altogether like that of Laburnum Adami, 
which often shows vegetative reversion to one of the parent forms, and whose 
seeds give rise not to L. Adami, but to L. vulgare. STRASBURGER, who 
always has consistently opposed the reality of graft hybrids on cytological 
grounds, has taken up the new Solanum forms, calling them hyperchimeras, 
that is, more or less complicated chimeras, in which the elements of the two 
parent forms are more or less intermingled but without any real nuclear 
fusion (see below).7 Of much greater significance are some recent investiga- 
tions by Erwin Bavr, and his results bid fair not only to cause a different 
interpretation to be placed upon WINKLER’s results than has been made by 
either WINKLER or STRASBURGER, but to revolutionize our notions along 
certain lines as to the possibilities of plants. BAuR has found from a careful 
study of geraniums with white-margined leaves’ that the green cells and color- 
less cells each are descended from others of their kind, the peripheral portions 
(composing two or three rows) being colorless (though containing chromato- 
phores) and the internal portions green, and the limits between them being 
s WINKLER, Hans, Weitere Mitteilungen iiber Propfbastarde. Zeitschr. Bot. 
I: he 345. pl. 1. figs. 4. 1909; see Bor. GAZETTE 48:478 
, Ueber die Nachkommenschaft der Solanum- —— Peay 
2 
Chromoeomenanhlen ihrer Keimzellen. Zeitschr. Bot. 
GAZETT 
TRASBURGER, EDUARD, ae or zur Frage der Propfbastarde- 
Ber. Deutsch. Bot Gesell. 2°77: 511— 90g. 
8 Baur, Erwin, Das Wesen a ‘die Erblichkeitsverhaltnisse der “Varietates 
albomarginatae Hort.” von Pelargonium sonale. Zeit. Abst. Vererbungslehre 1° 
339-351. figs. 20. 1909; see Bor. GAZETTE 48:72. 1909 
