The Chromosome and Its Division 13 



fluence of forces within the whole, which may be called "field forces." 

 These subunits, further, are controlled in their duplication by a 

 "substance" or field action working over the whole; they are subject 

 also to a polarized force or gradient originating in the centromere or 

 its surroundings. This would mean that the division of the chromo- 

 some is not simply the sum of the divisions of the self-duplicating 

 genie units, but is a feature of the entire chromosomal unit, involving 

 fields and gradients in addition to the self-duplicating parts. This 

 again means that a ground substance, a kalymma or whatever it may 

 be called, must be present which, in analogy to the cytoplasm of the 

 ciliate, is the seat of the coordinating substances, fields, and gradients. 

 This non-genic part of the chromosome contains only one self-dupH- 

 cating part, the centromere. The rest may be considered as growing 

 by accretion and dividing by fission. 



It is obvious that this discussion has a considerable bearing upon 

 the problem of what the genie material is in the chromosome and 

 what its organization is. It clearly points to an over-all organization 

 of the chromosome in which the self-duplicating genie parts are not 

 independent of the whole, as opposed to the genie string of the classic 

 theory. The only alternative would be that the chromosome is a single 

 immensely folded and coiled molecule, a simplification which could 

 hardly meet the facts of cytology. Again we must warn against making 

 the leap from a DNA molecule to the whole chromosome too light- 

 heartedly. We shall return to this point below, when studying Watson 

 and Crick's model of the structure of nucleic acid, revealing a new 

 type of template-like self-duplication and its relation to genie material 

 and chromosomes. 



The argument will become still more cogent if we add a few more 

 relevant facts in regard to Lwoff's findings on the self-duplicating 

 kinetosomes and the organelles derived from them. There are a few 

 more important facts to be added which relate to the field action 

 already mentioned. First (Lwoff), the realization of the potencies of 

 the kinetosomes of the ciliates depends upon their localization within 

 the proper cytoplasm, that is, their respective chemical surroundings. 

 Second, the behavior of the differentiations of the ciliate body during 

 division involves: (1) the formation of two morphogenetic fields 

 within the cytoplasmic body which control subsequent processes; (2) 

 the destruction of all differentiations based upon the products of the 

 kinetosomes; (3) the division of one or a few kinetosomes and the 

 distribution of the daughter granules (or fibers) in the two fields; (4) 

 the formation of "anarchic fields" of kinetosomes, and finally their 



