NOTES AND LITERATURE 



HEREDITY 



A Case of Non-Mendelian Heredity. — That hereditary characters 

 which behave in accordance with Mendel's law of se<:rev:at ion 

 depend in some way upon the chromosomes can hardly he ques- 

 tioned. I !i< ill .-ists. however, have hern loath to believe that all 

 hereditary characters are thus related to chromosomes. It is es- 

 pecially gratifying, therefore, to find completely worked out a 

 type of inheritance which differs radically from the Mendel ian 

 type and which appears to be entirely cytoplasmic in character. 

 The law of transmission in this case is of unusual interest. The 

 case is reported by Dr. Erwin Baur, of Berlin. 1 



In this paper Dr. Baur describes several types of variega- 

 tion. The first consists of variegation due to pathological con- 

 ditions (auto-infection or auto-intoxication) and is not hered- 

 itary. By overcoming the auto-intoxication such plants are con- 

 verted into ordinary green plants. On the other hand, ordinary 

 plants can be infected with this condition by graft-symhiosis 

 with an infected plant. This condition is not transmitted by 

 seed. It is called by the author "infectious chlorosis," and 

 is accompanied by a partial loss of green pigment in the chloro- 

 phyll grains. Several previous papers on this type of chlorosis 

 by the author are referred to. 



The second type of variegation consists of fully constant 

 races whose chroniatopliores carry a diminished amount of green 

 color i ni: matter, but the normal amount of yellow coloring matter. 

 These races have distinctly yellowish-green leaves. In crosses 

 with green races the yellowish green behaves as a Mendelian 



The readers of this journal will remember that a similar char- 

 acter in tomatoes was reported recently by Professors Price and 

 Drinkard. of the Virginia Experiment Station, and the character 

 in this case behaved also as a Mendelian recessive. 



