242 BOTANICAL GAZETTE [APRIL 
The original purpose was to test the matter of localization of 
the supposed alterations by which discontinuous variations occur 
in hereditary lines, a matter to which attention was directed by 
the suggestion of DeVries that mutations as exemplified by the 
derivatives of the oenotheras were consequent upon changes in 
the germ-plasm ensuing previous to the reduction divisions, and, if 
such localization were established, it was hoped that new muta- 
tions might be induced experimentally by controlled conditions 
or reagents. 
As has been pointed out recently, CHartes Darwin had 
attempted to induce alterations in leaves by the injection of 
reagents which might have acted after the manner of the sub- 
stances to which galls are due, but this effort was unknown to 
me, and it may be stated that no results of any kind were 
secured by him (6). 
The announcement of the preliminary results to be described 
here brought out the information that various workers had placed 
the bases of excised inflorescences and branches in solutions in the 
effort to cause embryogenic alterations, and also that specialized 
water cultures had been used, but without result. 
The initial tests were so planned as to include the introduction 
of solutions into the ovary at a time when pollen and egg were 
in the stage immediately preceding fertilization. Two plants 
were chosen for the first trial: Oenothera biennis, the form know? 
to American botanists as growing wild under that name; and 
Raimannia odorata, native to Patagonia, and now distributed 
about the world. Pure-bred material of both species, which had 
been guarded from possible intercrossing since its introduction 
into the cultures, was available. Thousands of individuals of 
many generations of both plants had been cultivated, and in n° 
single instance has anything beyond the well known forms of 
fluctuating variability been shown, except when diseased plants 
were encountered. Better authenticated material would be diffi- 
cult to procure, although, as was proven later, the mechanical 
conditions offered by the reproductive apparatus of these plants 
were of such character as not to facilitate the treatment. 
It was realized very quickly, however, that the use of the 
