INHERITANCE THROUGH SPORES. 



By JOHN M. COULTER, A.M., Ph.D. 



(Read April 14, i()i6.) 



The modern history of botany is a series of segregations of sub- 

 jects. Each new segregate has attracted a certain number of re- 

 cruits from the older subjects. There have always been two cate- 

 gories of botanists : those who move on promptly to the newer 

 phases of their subject, and the old guard that never moves on. The 

 latest segregate of the series is plant genetics, which is making so 

 large an appeal to botanists that if the epidemic continues all bot- 

 anists are in danger of becoming geneticists. What I wish to pre- 

 sent has a bearing upon the work of this important modern field of 

 botanical activity. In this presentation, however, I shall not intro- 

 duce the details of material. These details are too numerous for 

 the time allotted, and too technical for any audience excepting one 

 of professional botanists. 



Plant geneticists have begun, just as did plant morphologists, by 

 using the most complex material. So long as plant morphologists 

 focused their attention upon seed plants, they were accumulating 

 data that could only be interpreted empirically. When they in- 

 cluded a study of the lower forms, the simpler groups became keys 

 to the more complex ones, and interpretation became scientific. In 

 plant genetics w^e are still mainly in the stage of complex material. 

 Sexual reproduction is selected as the method of reproduction to be 

 investigated, and the particular sexual structures selected are so 

 peculiarly involved with other structures that it is impossible to 

 analyze the factors involved in the results. Not only are the sexual 

 structures beyond the reach of observation and of experimental 

 control, but there is an alternation of two forms of reproduction, 

 inheritance being carried through one generation to express itself 

 in the next. 



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