1899] MICROSCOPICAL JOURNAL. l3l 



Many stains were tried; especially iron-ha^matoxylin 

 and Bordeau red, ruthenium red and thionin, etc.; but the 

 best results were obtained from Flemming-s' triple stain, 

 safranin, g-entian violet, and orang-e G. 



In the resting- condition of the pollen-mother-cell the nu- 

 cleus is quite large. It contains one or two large nucleoli 

 which stain very readily with safranin and sometimes ap- 

 pear to be vacuolated. The chromatin, which is in the 

 skein stage, stains blue with the g-entian violet. As soon as 

 the chromatin breaks up and forms the chromosomes it 

 stains red with safranin. The chromosomes appear as 

 small oval bodies which are invariably situated in contact 

 with the nuclear wall. The larg-est number that was ob- 

 served in polar view was twelve. The linin appears in the 

 form of a lumpy or granular thread ; it stains blueand is in- 

 variably connected with the chromosomes. 



The cytoplasm now appears in the form of a clear retic- 

 ulum. The meshes of this network, which can be traced 

 from the nuclear wall to the cell-wall, appear to be smaller 

 and radi9,lly elongated in the immediate neighborhood of 

 the nucleus ; but they increase in size as one follows them 

 outwards and are comparatively large towards the cell-wall. 

 Scattered irreg-ularly throug-h the cytoplasm are numer- 

 ous small spherical bodies. These bodies have the ap- 

 pearance of oil-globules in the living- cell, but after the cell 

 has been killed in Flemming-'s fixing- fluid they appear 

 quite black. 



SUMMARY. 



The observations made upon the formation of the spin- 

 dle in Cobcea may be briefly stated as follows : A granular 

 substance gradually accumulates and forms a complete 

 zone around the nucleus. This zone is designated peri- 

 karyoplasm. Upon the breaking down of the nuclear wall 

 the linin of the nucleus and the perikaryoplasm form a 

 network which occupies the central portion of the cell. 

 This network g-rows out into several projections which be- 

 come the cones in the multipolar fig-ures. The spindle- 

 fibres are formed by the elongation of the meshes of the 

 network in the direction of the projections. The cones 



