438 



WATASE. 



[Vol. VIII. 



cases microsome appear as varicosities on 

 without any visible cross-threads. This latter 

 be due, in some cases, to the plane of the cr 

 in position which makes them invisible in a 

 it may be due to the technical difficulty of 

 extremely delicate cross-threads in a certain 

 these remarks, however, apply to those cases 



a single thread, 

 appearance may 

 oss-threads lying 

 given section, or 

 preserving such 

 cell. Neither of 

 in which the mi- 



As. 



Fig. 5. 



Eq.M 



C W-" 



As.f 



M 



Fig. 5. Diagram of a dividittg cell, showing the cytoplasmic framework of the 

 caryokinetic figure and its relation to the rest of the cell-body. The chromosomes 

 and the spindle fibres which are directly concerned with their division are 

 omitted from the diagram. C. C, Centrosomes ; S., Spindle filaments ; M., 

 microsomes or Cyto-microsomes ; Eq. M., Equatorial microsomes or "cell-plate," 

 the "microsomes chrotnatiq7ces" of Guignard ; As. C, '■^ Astroccele" (Fol), the 

 "zone mt^dullaire" of the attractive sphere of E. van Beneden ; As. f., fibres of 

 the aster, vnth microsomes imbedded in the substance of each fibre, giving rise 

 to the varicose appearance. The diagram is especially intended to show the 

 distribution of the microsomes in different parts of the cell. 



crosomic varicosities appear in the substance of straight spindle 

 filaments without any cross-branches. It further appears prob- 

 able that the substance of the cytoplasmic thread and that of 

 the microsome stands in a certain genetic relationship. In 



