THE PHYSICAL BASIS OF LIFE 



17 



organization, or organized only luider the domination of 

 the nucleus. We have been accustomed to think of its his- 

 tory in cell-diyision as a simple mass-diyision showing a 

 fmidamental conti'ast to the complicated meristic process 

 seen in nuclear diyision. Facts are howeyer slowly accu- 

 mulating which may compel a revision of this notion. Re- 



A 



F 



FIG. 7 

 Cell-division in the spermatocytes of the hemipter Eiiscliktus showing the behavior 

 of the chondriosomes (from BowEX). These have heie the form of nxmierous 

 rods (black), Avhich in F are seen separating into two groups as the cell divides. 



cent cytological studies bring prominently into view the 

 fact that many of the formed bodies are directly trans- 

 mitted, either as such or in the form of pre-existing spe- 

 ciiEic material, from mother-cell to daughter-cell. And 

 there is growing evidence that this operation is not an in- 

 cidental hit or miss process, as formerly supposed, but 





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