- r.i - 



ceiitrioles. AfttM" thai the nucleus aud spindle atljoiuiiiij: to 

 it stretch to a ^n-eater Icn.nth and the iiueleus-nKMnltraiir (pre- 

 served throui^'houl all the division) becomes constricted, thus 

 I'orniinL'' two dau.n'hter nuclei connected only by means (d 

 the spindle (tab. III. tin'. :u). With the further ^Towth of 

 the spindle the nuclei gradually diver^-e wider (tab. Ill, I'i^-. M). 

 Already K'ucinsky (2()) su^-^*ested that the j^-rowth of 

 the spindle is very essential in separating- the dau^- 

 liter-nuclei. In Mj/.ro)no)tas the divergence of the daug- 

 hter-nuclei ill the midst of a protoplasm rille<l with food 

 meets with .u'reat difficulties, ancJ the spindle in this case 

 plays a very important role. The spindle in the manner of a 

 ^ifrowiuj;' elastic rod forces its way through the inclusions of 

 the plasm, and with its ends draws the daughter-nuclei to oppo- 

 site sides. In such cases the plasm is sometimes so resistant, that 

 the spindle bends into an acute arch, and the latter, probably, 

 quickly straightens, which leads to the divergence of the daug- 

 hter-nuclei. The daughter-nuclei, besides diverging one from 

 another, very often turn one to the other aroujid the axis 

 formed l)y the spindle (tab. Ill, fig. ;57). This turning is 

 evoked owing to the particular structure of the spindle. 

 The spindle is composed of a rather great number of 

 fibrils, which run from one of its ends to the other not 

 directly, but becoming slightly twisted (as the fibres in a 

 rope, see fig. 36, tab. III). Before the nucleus has divided the 

 spindle-fibrils maintain this arrangement, but as soon as two 

 nuclei are formed, the elastic fibrils of the spindle strive to 

 get out of the twisted condition, to straighten, and their 

 ends unfold in ojiposite directions forcing the daughter-nuclei 

 to turn as described above. 



The daughter-nuclei gradually assume the structure of the 

 resting state. This process may be more or less speedy. 



After the forir.ation of the daughter-nuclei, near each of 

 them a new undulating membrane begins to form. The mem- 

 branes are formed from the ends of the spindle, more 

 correctly — from the centrioles lying at both ends of the 

 spindle. First fine threads are seen to be leaving the ends 

 of the spindle. They are closely apposed to the nuc- 

 leus and form around it nearly a semi-circle (tab. Ill, fig. 34). 

 They are the rudiments of the membrane base,- namely, of 

 the anterior part of the base which in tyi)es A and B clasp 



