No. 581] GERM CELLS AND SOMATIC CELLS 



295 



tissue indefinitely; 11 these experiments ought to be ex- 

 tended; especially m'm lit it be of interest to use the direct 

 descendants as hosts for the tissues of the parent. It is to 

 be expected that the quality of the parents which makes 

 the body fluids suitable for their own tissues might make 

 them likewise suitable for certain of their offspring. Such 

 experiments I began some time ago and I expect to 

 continue them if opportunity should present itself. 



The growing of tissues in culture media, which excludes 

 attack on the cells by connective tissue and lymphocytes, 

 may also serve the same purpose and quite recently has 

 been used through a larger number of generations. But, 

 as stated above, we have in these experiments merely to 

 deal with an attempt to confirm the potential immortality 

 of the somatic cells which had in principle been estab- 

 lished through previous investigations on the life of tumor 

 cells. 



While thus various kinds of tissues of an organism have 

 the potentiality of an immortal life, separated from the 

 organisms to which they belonged, the organism as a 

 whole invariably dies and with it its component tissues. 

 This is evidently due to the interdependence of various 

 parts of an organism and to the death of certain sensitive 

 cells, especially the ganglia cells of the central nervous 

 system. We might therefore be inclined to conclude that 

 these ganglia cells do not possess the potentiality of im- 

 mortal life. But even in the case of the ganglia cells, 

 which are of such significance for the life of the organism 

 as a whole, we can at present not deny the possibility that 

 they also may have the potentiality of immortality and 

 that they merely succumb under the influences of certain 

 injurious conditions arising in the organism. On the 

 other hand, fully developed ganglia cells have apparently 

 lost the power to multiply; they are furthermore sensi- 

 tive to certain insults to which other tissues show resist- 

 ance. Tims the unfavorable condition prevailing during 



directly afterwards seems to be sufficient to cause the death 



