295 



XI. — Preliminary Tests on the Homologue of the Golgi 

 Apparatus in Plants. 



By A. H. Drew, D.Sc, RE.M.S. 



{Bead April 21, 1920.) 

 Four Text-figures. 



At the March Meeting of the Eoyal Microscopical Society I 

 demonstrated certain cytoplasmic inclusions in the cells from the 

 root-tip of the onion closely resembling or identical with the 

 Golgi apparatus of animal cells. Guilliermond {!)* has recently 

 described similar appearances in the roots of the pea and barley as 

 filamentous mitochondria, and noted their resemblance to the 

 Golgi apparatus. The present note puts on record the appearances 

 seen in the onion and the method used. 



Growing root-tips are fixed for twenty-four hours in formol, 

 20 com. ; cobalt nitrate, 2 grm. ; sodium chloride, 8 grm. ; water 

 to 100 c.cm. (preferably at 37° C.). Frozen sections are cut after 

 soaking in gum-syrup for at least an hour. The sections, after 

 washing in water, are fixed on gelatin-coated slides with formalin, 

 rinsed in water to remove excess of formalin and mordanted at 

 50°-55° C. in chromic acid, 4 p.c, osmic acid, 2 p.c, equal parts, 

 on the slide for varying periods — fifteen minutes to one hour or 

 longer. The staining is tlien carried out as follows : — 



Einse in water and stain with iron-alum, 3 p.c, fifteen minutes, 

 followed by J p.c. hematoxylin fifteen minutes at 50° C. Differen- 

 tiate in 3 p.c. iron-alum, cold, till the nuclei are pale brown, transfer 

 to 2 p.c. pyridin two minutes, wash in running water two to five 

 minutes and mount in xylol-balsam. 



In specimens chromated for the shorter periods, the mitochon- 

 dria only are visible in addition to the nuclei. These are usually 

 of the granular variety, but also occur as very fine short rods 

 staining very black with heematoxylin. They are extremely 

 numerous and are scattered over the whole of the cytoplasm (see 

 fig. 1). The mitochondria may also be well seen when stained by 

 Hollande's chloro-carmine {2), but the Golgi apparatus is not 

 stained by this method. In sections mordanted with the chrom- 

 osmic solution for longer periods, it is found that the mitochondria 

 stain very much more faintly, and new structures begin to make 



* The italic figures within brackets refer to the Bibliography at end of the 

 paper. 



