542 Theophilus s. Painter, 



noted here, however, that in some of the dividing cells, the ctetosomes 

 have not been observed to be attached to the accessory bodies, but 

 wherever the latter bodies were favorably placed for observation, 

 the ctetosomes have been found, and hence it has been concluded 

 that they are present in all of the cells but are hidden when the 

 accessory lies in certain positions. It should be also pointed out 

 that as a result of the first division, all of the second spermatocyte 

 cells carrying the accessory chromosomes carry the ctetosomes. 



Planosomes. 



The time when the planosome may appear in the spindle is 

 variable. Very exceptionally, as shown in Fig. 74, the planosomes 

 go to the poles early. More usually, however, we do not see so 

 many of these bodies until after the autosomes have gone apart. 



The planosomes may divide during the first maturation mitosis, 

 but the time when this occurs varies with the cell. In Fig. 74, we 

 have a cell in which the planosomes have divided at the time 

 when the accessory chromosome was passing to one pole. This is 

 unusual. In the cells shown in Figs. 75 and 77, we have the 

 typical behavior of these bodies. Here they are lagging behind in 

 the spindle until the cell walls of the daughter spermatocytes are 

 formed. Very careful focusing will show usually, that these plano- 

 somes have individual fibers of their own. The fact that they may 

 divide would imply this, of course. 



Not only do the planosomes vary in the time of their division 

 but there is much variation in the number seen in the different 

 cells, dependent, perhaps, on the fact that the time of division 

 differs with each individual cell. Counts made at this time are of 

 little value because of three sources of error. The first of these is 

 the fact that the time of division varies so that one never feels sure 

 that he sees all the planosomes. Again is is always possible that 

 these small bodies may be hidden by some autosome. The third 

 source of error lies in the fact that after long extraction of the 

 stain, the planosomes tend to disappear. It is obvious that it would 

 be impossible to state the exact number of planosomes in the cells, 

 and further it would be equally impossible to say whether all 

 of the cells bear the same number of these bodies. A limited 

 number of observations will be given, however, as these will be 

 verified in the later stages. 



During the rest period, the largest number of small nucleoli 



