FrenzeVs Afcso::oon Salinclla. 469 



and the two daughter individuals arc, althougli less separated 

 than they subsequently become, already present before the 

 nucleus has divided. 

 Tin-: NUCLEUS of the parent individual which remains 



UNDIVIDED BELONGS TO NEITHER OF THE DAUGHTER INDI- 

 VIDUALS; THE LA'ITER ARE THEREFORE IN THE STAGE OF THE 



NON-NUCLEATE Protoblast. But since, for the full 

 ACTIVITY of the Protoblast, the nucleus has become an organ 

 of already indispensable importance, they must in the onto- 

 geny receive a nucleus much earlier than may have been the 

 case in the phylogcny. The appearance of important organs 

 relatively earlier in ontogeny than in phylogeny is an occur- 

 rence which has indeed met with general acceptation since 

 the writings of Fritz Muller. The unappropriated parent 

 nucleus, which is left behind, is the more unable to lead an 

 independent life, and relapses into its constructive parts : the 

 daughter individuals hasten to divide among themselves this 

 material, which is so important for the building-up of their 

 further organization, and to construct from it a nucleus for 

 themselves, after the pattern of that of the parent form. 

 Consequently the object also of the more or less 

 complicated forms of nuclear division appears to be 

 nothing further than an ontogenetic abbreviation op 

 the phylogenetic process of the formation of the 

 nucleus from the material substratum, to which the 



HEREDITARY SPECIAL PROPERTIES ARE UNITED. ThIS SUB- 

 STRATUM, THOUGH NOT AS YET CONCENTRATED IN THE SHAPE 

 OF THE NUCLEUS, AN ORGAN SUBSEQUENTLY SO IMPORTANT, 

 CERTAINLY BELONGED ALSO TO THE NON-NUCLEATE STAGE 

 IN THE PHYLOGENY *. Sincc, therefore, the nucleus, althougli 

 as an organ more important than ever, has been to a certain 

 extent dethroned, the Protoblast without a nucleus, no matter 

 whether or not there still exist non-nucleate forms capable of 

 independent life, may assume its rights once more. 



The non -nucleate Protoblast, therefore, as the initial stage 



* The further circumstance that daughter-cells wliich have been produced 

 by simple fission do not (or less frequently) form other organs also (chro- 

 uiatophores, vacuoles in plants, circlets of cilia, collars, &c, in Protozoa) 

 quite afresh by themselves, but acquire them by division of the organs in 

 question belonging to the parent-cell, must, I consider, likewise be re- 

 garded as an ontogenetic abbreviation of the original process of the origin 

 of those organs. In cases, however, where the ontogeny of the cell repro- 

 duces its phylogeny more faithfully, e. g. in the development of vmicellular 

 and multicellular creatures from spores, the organs of the parent-cell, with 

 a view to formation of spores, degenerate before division takes place, and 

 the daughter-cells or their successoi-s are obliged to reconstruct these 

 organs, with the exception of the nucleus, afresh for themselves. 



