117 



III. — A New Mitotic Structure disclosed as the Result of 



New Technique. 



By E. Sheppakd, F.E.M.S. 



(Bead March 17, 1915.) 

 Plate IV. and Pig. 15. 



For some time past I have been experimenting with different 

 stains and staining processes, in order, if possible, to obtain 

 further knowledge relating to various mitotic structure, little 

 anticipating at the commencement of my work that my efforts, 

 and the comparatively few trials which I made, would so soon be 

 rewarded. From the outset my object was to increase the stain- 

 ing power of the spindle-fibres and other archoplasmic structure 

 that might be present in the vegetable cell. 



I was of opinion that if this could be achieved, and any im- 

 provements upon the results obtained from present-day technique 

 achieved, the best line on which to proceed was to use mordants 

 suitable to the different stains with which I was about to experi- 

 ment. 



It is not necessary for the purpose of this paper to describe the 

 various single and combination staining baths with which I ex- 

 perimented, but I may mention that the majority gave poor results, 

 and others no better, if as good, as those obtained with standard 

 formula?. 



My best results have been obtained with the mordanted aniline 

 dyes used in conjunction with Heidenhain's iron-hrematoxylin 

 method. 



With this combination carefully and successfully applied, a 

 single trial will fully convince the worker what wonderful contrast 

 and magnificent crisp definition may be obtained. There are 

 doubtless many other aniline dyes which may be similarly worked 

 in conjunction with Heidenhain's iron-hrematoxylin process, and 

 possibly may give even more gratifying results than those which 

 I have already obtained, and open up a wide range of work ; to 

 this I hope to return when time permits. 



For the present, though, I have been experimenting for but a 

 short time with this special branch of cytological technique, and 

 have confined my investigation entirely to the bringing out of 

 mitotic structure in the vegetable cell ; the results have been so 

 pleasing and startling that I have felt compelled to write a short 



