26 EI SEN. [Vol. XVII. 



which pass from the chromoplasts, and the other set merely 

 strings of chromioles which pass into the chromoplasts, again 

 to be expelled from them into the regular leaders. The 

 formation of the chromomeres would, of course, take place 

 in the regular leaders, or possibly even in the chromoplasts. 



Auxocyte in the " imperfect resting stage," showing the formation of leaders consisting 

 of round chromioles surrounded by a film of chromoplasm. The leaders start from two 

 chromoplasts of unequal size, both containing endochromatic granules. The leaders are 

 connected by a linosomic network. Four linoplasts. In the cytoplasm are seen the two 

 spheres, the inner one, the granosphere, containing the archosome. There are eight acces- 

 sory archosomes, some in the plasmosphere, others in the cytoplasm. The two spheres 

 are of a foam-like structure. The cytoplasm is only partially indicated. 



The Chromosomes. — The chromosomes are not in any sense 

 permanent organs of the nucleus. They arise, disappear, and 

 are re-formed as the case requires ; in fact, are mere convenient 

 structures for the proper division and nourishment of the 



