86 EISEN. [Vol. XVII. 



permanent granules of the chromosomes, with the exception of 

 the chromoplasts, are possibly the carriers of heredity. The 

 chromioles in each chromomere are kept together by a special 

 chromoplasm, just as the centrioles are united by a somosphere. 



V. The evolution of the chromosomes is directed by one or 

 several bodies — the chromoplasts which collect the chromioles 

 by the aid of the linin into leaders. The number of finished 

 leaders is constant, being as many as there are to be chromo- 

 somes. The chromosomes are formed by contraction of the 

 leaders and by the formation of chromomeres, each with a 

 certain number of chromioles. The chromoplasts are character- 

 ized by the endochromatic granules, which probably constitute 

 a food supply for the chromioles. The chromoplasts stain as 

 the chromoplasm. They divide finally in as many parts as there 

 are chromosomes, one part remaining attached to one end of 

 each chromosome, thus constituting a landmark by which the 

 location and position of the chromosome can be recognized, and 

 by which its mitosis can be determined. In the confluent 

 umbrella stage the chromosomes and the chromoplasts fuse 

 completely. 



VI. The linoplasts or true nucleoli supply the material and 

 the nutriment for the linin network whenever an unusual supply 

 is required, as, for instance, when the split halves of the leaders 

 are to be spread apart. After this separation is effected the 

 linoplasts disappear and the linin network is disarranged and 

 its granules distributed and mixed with the cytoplasm of the 

 cell. The linoplasts consist principally of the same kind of 

 granula as the linin, with the addition of paralinin globules. 

 The nuclear membrane is formed by a condensation of linin 

 granules. 



VII. The structure of the archosome and the accessory 

 archosomes is the same, and the latter are derived from the 

 former through budding. The archosome when not in activity 

 is generally found in the granosphere, while the accessory arch- 

 osomes are at the same time found in the plasmosphere. The 

 archosome directs the formation of the spindle and of the fibers 

 generally. The fiber cones are, however, presided over by the 

 accessory archosomes. These latter bodies are also intimately 



