130 REPORTS ON INVESTIGATIONS AND PROJECTS. 



soon as seeds were obtained these were planted to obtain a second generation, 

 A few plants were obtained, which in every particular conformed to the new 

 type and exhibited no return to the parental type. 



Injections of the ovaries of Oenothera biennis were followed by the pro- 

 duction of one individual, which was recognizably different from the parental 

 type in many qualities, some of which were plainly apparent even in the 

 earliest leaves of the seedlings. 



Like the other derivative induced by the action of the chemical reagent, this 

 form also transmits its qualities to the second generation. The parental 

 form has been under observation for five years in cultures and in a wild 

 condition. An aberrant form which appears to be ever-sporting has been 

 previously figured, and while this form appeared in the injected or treated 

 seeds in a normal proportion, yet the newest aberrant has not been seen 

 elsewhere. The probability must be taken into account that it may be a 

 mutant of rare occurrence, the cycle of which came within the experiments, 

 but in either case it is plainly a mutant, and it only remains to be seen 

 whether or not it was induced by the action of the zinc solution. The pre- 

 sumption seems to favor such a conclusion. 



The atypic forms which have been tested to the second generation in both 

 species are found to constitute mutants in the sense in which that term is used 

 by de Vries, and are real and actual departures from the course of the 

 hereditary strain. The capacity of the mutants induced in this manner for 

 survival would depend entirely upon the environment into which they might 

 be thrown. 



The results of this experimentation have the additional interest that some 

 simulation of their action may be reasonably predicated in nature. Thus the 

 effect of radioactive substances such as spring and rain waters, the gaseous 

 emanations in volcanic regions, the accidental and unusual formation of 

 certain enzymes or substances in the vicinity of the egg-cells or pollen mother- 

 cells, or the action of substances set free by foreign pollen which might pene- 

 trate to the region of the egg-cell in which pure fertilization ensued, or the 

 stings of insects with the attendant liberation of inciting substances might 

 well exert a similar action. 



It is also to be noted that in these experiments the possibility is by no 

 means eliminated that the reagents injected into the ovaries may not aft'ect 

 the egg-cell alone or at all, but may influence the elements carried by the 

 pollen tube as it penetrates the placental tissues on its course to the egg-cells. 



Two instances of sports or branches which bore characters not character- 

 istic of the shoot of the species on which it was found were tested. In both 

 cases the characters of the sport or variant were found to be fully inheritable 

 without any admixture of the qualities of the main shoot of which the sport 

 was a branch. 



