88 CeU-Pedigrccs 



other cells of the sporangial tissues must be regarded as 

 twigs. For here, too, the branches possess the power of 

 continuing the pedigree, but the twigs do not. 



On germination the spores produce the male and the 

 female prothallia. The former bear only the male sexual 

 organs or antheridia, the latter only the female organs 

 or archegonia. In the cell-pedigrees we again imagine 

 heavy straight lines for those cell-sequences which lead to 

 the egg-cells and to the spermatozoids. These represent 

 for us the branches, all the others the twigs. 



We have arrived at the completion of our sketch,^ 

 since we have been through the much ramified path from 

 the fertilized egg-cell to the new germ-cells, and have 

 taken in its numerous side-paths. Let us glance once 

 more over the whole, and we shall see that, by empha- 

 sizing the branches instead of the twigs we have, in spite 

 of the great complication a simple and clear picture. For 

 the branches again, we have to make a distinction be- 

 tween the fertile and the sterile. Only the former lead 

 finally to egg-cells, or to spermatozoids, i. e., to new in- 

 dividuals; the sterile branches do not do this. Funda- 

 mentally, then, they behave towards the fertile ones like 

 the twigs ; they take no part in the pedigree of the species. 



4. The Main Lines in the Cell-Pedigrees 



For those cell-sequences, which in the cell-pedigree 

 lead from the fertilized egg-cell through the individual 

 to the next generation, I may, as a continuation of Weis- 



3In order not to complicate the illustration I have not discussed 

 here the vegetative multiplication. I shall come back to it in the next 

 Section. 



