1915] 



MACDOUGAL — MODIFICATION OF GERM-PLASM 267 



part in a thousand. Fifteen to forty ovules had been touched 

 by the color in young flowers not yet open. A much larger 

 number had been colored in the ovaries of mature flowers. 

 This solution was introduced into ovaries of the scrophularia 

 under examination (fig. 3). Young ovaries in this plant 

 showed very few ovules affected, none in a few cases. Older 

 ovaries in which fertilization had probably taken place showed 

 as many as 15-20 colored ovules. Probably only a small pro- 

 portion of the ovules affected would have survived and de- 

 veloped into viable seeds, so that many of the treated ovaries 

 would have yielded nothing but normal seeds. This condition 

 is to be taken into account by those who do not recognize the 

 technical difficulties in the way of duplication of any particular 



treatment. 



The recent results of Churchman and Russell 1 in securing 

 stimulation of the growth of animal tissues with methylene 

 blue suggest that this substance might produce some effects 

 on the embryo-sacs of plants, and also the advantage of using 

 a reagent the diffusion and penetration of which are visible 

 and obvious. 



It was desirable to use this dye in obtaining some knowledge 

 of the probable action of other solutions in Scrophularia, so 

 tests were made with this plant. A number of ovaries on a 

 detached shoot in the laboratory were placed in a solution of 

 one to a thousand at 9:30 a. m. Material was taken for ex- 

 amination at suitable intervals. 



The placental walls and funicles were stained in part within 

 a half hour. Two hours later the color had advanced well 

 along the conducting tract in the funicular stalk. Five hours 

 after treatment a notable amount of the dye had been carried 

 clear to the embryo-sac, where it stained the nucellus and the 

 antipodal region deeply. It is to be noted that the material 

 was still alive and that this material if left attached to the 

 plant would have developed some mature seeds in all proba- 

 bility ( fig. 3 ) . 



1 The effect of gentian violet on protozoa and on growing adult tissue. Soc. 

 Exp. Biol, and Med., Proc. 2: 124. 1914. 



