Genie and Non-genic Parts of the Chromosome 43 



at the time of reduplication the genie material is reduced to the 

 single molecule (of each kind) level to be reassembled consecutively 

 in the chromosome. Even then the arrangement of the DNA in the 

 chromomeres of the non-dividing chromosome remains a riddle. A 

 large chromomere must contain a huge number of molecules of DNA. 

 If they were attached to the protein, according to Astbury, an ex- 

 tremely complicated globular arrangement would result, an equal 

 division (re-creation) of which is difficult to imagine, though we have 

 already mentioned one possibility, a whorl structure of the chromo- 

 mere which could be unfolded at the time of duplication. It is very 

 diflBcult to fit this into the cytological facts. In the lampbrush 

 chromosomes we have just the opposite situation. They are possibly 

 of the nature of a single immense molecule, but this has nothing 

 to do with chromosomal division. Quite the contrary, the two chroma- 

 tids have united! (Callan and others). We might conclude that the 

 chromomeric configuration has quite a different meaning, as also 

 the strange size law reported above indicated. This can only have 

 to do with the function of the genie material within the chromosome. 

 Even if we assume the correctness of the classic theory of the gene 

 which practically identifies chromomeres and genes, the difficulties 

 are not solved. Actually they are increased as we now have the 

 problem of self-duplication of the DNA-rich chromomeres and the 

 DNA-poor interspaces. 



In the lampbrush chromosomes of the vertebrate oocytes the 

 chromomeres sprout the petal-like arrangement of long loops attached 

 to the chromonema. There is no generally accepted interpretation 

 of the meaning of this configuration (I 2 A; see Gall, 1954; and Al- 

 fert, 1954). Ris considers the loops to be coils of the chromonema; 

 Duryee, Dodson, Guyenot, and Gall assume that they are products 

 of the chromomeres, functional elements which have nothing to do 

 with chromosomal structure, but with chromosomal function in the 

 growing oocyte. Their development and independent solubility are 

 in favor of such a view. However this may be, the actual chromonema 

 is about thirty times as long as the mitotic chromosome and, possibly, 

 of the diameter of a large chain molecule (Gall, Callan, Guyenot). 

 This may represent an almost maximally stretched molecular chain 

 of nucleoprotein. In some materials the Feulgen method reveals only 

 a few irregular concretions (Dodson); in other materials, chromo- 

 meres are arranged in a typical way and have been described as 

 appearing in the center of the whorl of loops and even with one 

 chromiole (Guyenot) for each loop. It seems that the DNA, here 



