44 EISEN. [Vol. XVII. 



either direct or actually furnish some substance to the contrac- 

 tile fibers. They are, during the metaphase and anaphase 

 stages, found in close proximity to the points from which these 

 fibers start, and in several instances I have seen them actually 

 in contact with those fibers. It seems possible that an acces- 

 sory archosome is first placed in position on the outer side of 

 the centrosphere, and that it then gives rise to a contractile 

 fiber by budding (Fig. in). Again at other times (Fig. no) 

 we find these contractile fibers already formed, and yet in their 

 vicinity a number of accessory archosomes, arranged in a ring 

 around the archosome. Be this function of the accessory 

 archosomes as it may, certain it is that they also possess 

 another function of great importance, that of presiding over 

 the fiber cones and the pulling of the cytoplasmic membrane 

 away from the nucleus, while the latter is in a stage of growth 

 (Figs. 65-71, 1 1 4- 1 16). Thus at the end of the confluent 

 umbrella stage we find them at first situated on the cytoplasmic 

 membrane with fibers radiating out in several directions. They 

 soon, however, rise from the membrane, carrying with them 

 the fiber cones. As the ends of the cones remain attached to 

 the membrane, the latter is naturally pulled away from the 

 nucleus. There may be one or more accessory archosomes at 

 the pole of each fiber cone. When the fiber cones have per- 

 formed their function the accessory archosomes slide down 

 along the fibers and congregate in the vicinity where the new 

 granosphere is being reconstituted. This refers to the sper- 

 matocytes, as I have not found any fiber cones in the auxocytes. 

 Towards the confluent umbrella stage in the auxocytes the 

 accessory archosomes diminish in size, number, and staining 

 capacity, just as does the archosome. They next reappear on 

 the cytoplasmic membrane, but are not readily detected except 

 on sections which pass obliquely or excentrically (Fig. 65). 



A most interesting fact is that a large number of accessory 

 archosomes are thrown out of the cell into the intercellular 

 spaces, in which they sometimes remain free, sometimes re- 

 main attached to the outside of the cell membrane. (See the 

 chapter on paracellular bodies.) The centrioles in the archo- 

 somes vary in size and number. 



