458 XXXII. CELL-DIVISION AND NUCLEAE DIVISION. 



sections of the medullary rays. We now prepare new sections, 

 likewise tangential longitudinal, through the secondary cortex, and 

 lay them for a few minutes in a watch-glass containing a solution 

 of iodine (iodine 1, potassium iodide 1, water 200). The sections, 

 are then laid on an object-slide in a small drop of the same solution 

 and covered with a cover-glass. Sulphuric acid (1 volume acid to 

 3 volumes water) is then allowed to run in under the cover-glass. 

 The preparation now becomes darker. Similarly, from the edge of 

 the cover-glass is run in a small drop of methyl-violet solution (1 

 gram pyoktanin cceruleum of E. Merck, Darmstadt, in 30 c.c. water). 

 This is allowed to act for about three minutes, and then the slide, 

 cover-glass and all, is plunged into a dish containing about 400 c.c. 

 of water. The section is washed, and laid in glycerine upon a 

 clean object-slide. If the staining has been successfully performed 

 the membranes in the section are coloured bright blue, the proto- 

 plasts dark blue, and, similarly, the extremely fine protoplasmic 

 connecting threads traversing the membranes, of the presence of 

 which a suitably strong magnification will now convince us. 



Viscum album (the Mistletoe) may also be recommended as a 

 favourable object for the demonstration of the plasmic connecting 

 threads, sections of the inner cortex being again used for the 

 purpose. 



