92 Cell-Pedigrees 



the development mostly on the somatic tracks. It is only 

 with caution that we may utilize the latter in judging the 

 former. 



In the following chapter I will discuss more in detail 

 the germ-tracks and the somatic tracks in the cell-pedi- 

 gree of the higher plants. In doing so I shall divide the 

 former into primary and secondary germ-tracks. Both 

 lead from the fertilized egg-cell to the new egg- or sperm- 

 cell. The former ones, however, do so by the shortest 

 route, that is usually within one individual, and, in the 

 case of alternation of generations, through the usually 

 small number of individuals involved. The latter, on the 

 contrary, reach their end indirectly, by means of vegeta- 

 tive multiplication, e. g., through adventitious buds. They 

 may frequently pass through an apparently unlimited 

 number of individuals before returning to an egg-cell. 



