112 BOTANICAL GAZETTE [ FEBRUARY 
higher plants, but fails to account for the extreme polymorphism 
often observed in the first generation of hybrids between race 
of cultivated plants, or between closely related species, as for 
example some racial hybrids of maize and some specific hybrids 
of Lychnis and Digitalis. Mr. Swingle considered it necessay 
female nuclei. The male and female chromosomes probably 
persist side by side unchanged in number, and possibly unchanged 
in quality during the whole of the ontogeny of the hybrid, redue 
tion not occurring until the close of the first generation. It 
therefore necessary to assume, in order to explain the observet 
by the material bearers of heredity is, at least in some cas® 
function of their relative positions ; and further that in mos} 
cases the relative positions of these bearers of heredity, as deter 
mined at the moment of fusion of the male and female nuc® 
persist unchanged throughout ontogeny of the offspring. Som 
phenomena, such as reversions to the one or the other par 
form by a larger or smaller portion of the hybrid, would : 
explained by assuming some change in the disposition of y 
hereditary substance, whereby they assumed a new position 
partial or complete stability. The suggestion was made . 
possibly the difference between uniform and polymorphic hy ei 
of the first generation is due to a more complete interminglit 
of the hereditary particles in case of polymorphic hybrids (* 
spring of closely related organisms), whereby many di ee 
combinations would be possible, and in case of uniform hyPt 
(mostly cffspring of distinct species or very different as 
the same Species), to greater or less aversion to comminglté 
between the two more diverse sorts of particles, whereby ae 
would remain in two separate groups and affect ontogeny 
formly and equally. os 
Xenia, or the communication of paternal characters to pat 
of the mother plant in the immediate neighborhood of the ¢ 
x & 
