208 Pangens in the Nucleus and Cytoplasm 



scendents. To this end, however, they must, according 

 to the present state of cell-anatomy and of the study of 

 fertilization, be received into the nuclei. The hypothesis 

 of intracellular pangenesis obviously does not make such 

 an assumption; the pangens that have once left the nu- 

 cleus do not have to return to it, neither into the nucleus 

 of the same cell, nor into that of any other. 



It is true that, with our present anatomical knowledge, 

 the possibility of a transmission of pangens from one cell 

 to another cannot be denied. The researches of Tangl, 

 Russow, and many other investigators on the direct con- 

 nections of the protoplasts of neighboring cells by means 

 of the delicate pore canals of the pits, even indicate the 

 path on which such a passage might eventually take place. 

 In the latex vessels the currents of protoplasm are un- 

 doubtedly not limited to the individual constituent cells, 

 the current continuing without regard to the former cell- 

 limits. This is especially the case with the mass-move- 

 ment after injuries, and probably also with the proper 

 movements of the granular plasm in the normal state. If 

 we assume that all living protoplasm consists of pangens, 

 their passage from one cell to another cannot be denied 

 here. But this phenomenon is obviously of no importance 

 for the theory of heredity. Similar considerations could 

 be made for other cases of cell-fusions, or symplasts. 



The mode of origin of the secondary pores of the 

 Florideae, discovered by Kolderup-Rosenvinge,^" is also 

 worthy of note. The cortical cells, e. g., of Polysiphonia, 

 divide in the usual manner with preceding nuclear di- 

 vision. But one part contains almost the entire proto- 

 plast and the other but a small corner at its base. The 



^^Kolderup-Rosenvinge, L. Sur la formation des pores second- 

 aires chez les Polysiphonia. Botanisk Tidsskrift. 17: 10. 1888. 



