gy^ Douglas H. Campeell. 



As with T. Virginica, the best staining of the nuclei of the stamen-hairs 

 resulted from the use of a -002 ^ Solution and an immersion of from one 

 to two hours. Once especially a dividing nucleus was thus stained with 

 mauvein extraordinarily deeply, but with a Vie oil-immersion lens proto- 

 plasmic movement was still to be seen, although during the process of di- 

 vision the Streaming becomes very much reduced, and even where the cell is 

 unstained is generally hard to detect. In this [case the surrounding plasma 

 was also slightly colored, but very much less deeply than the nucleus itself. 



When first seen the cell-plate was just formed and the Segments of the 

 daughter-nuclei were well-differentiated and stained of an intense violet- 

 purple, so deep in fact as to raise some doubt as to the possibility of their 

 still being alive. The cell, however, was studied further, and the division 

 was found to proceed until the division-wall was complete and the daughter- 

 nuclei had assumed nearly the appearance of resting nuclei. In this stage the 

 chromatin was more uniformly distributed and the color of the whole nu- 

 cleus in consequence paler. Atthe eudoffive hours from the first Observation, 

 the movement of the protoplasm was if anything more marked than at first. 



In this case the color was quite as deep as in an ordinary haematoxylin 

 preparation. 



With mauvein and dahlia the nuclei of the stem-parenchyma cells were 

 colored as with T. Virginica. Treated wich methyl-violet the results were 

 also eminently satisfactory. A small drop of a -1 ^ Solution of the latter was 

 run under the cover-glass and allowedto remain for five minutes ; at the end 

 of this time the nuclei being well colored, the section was washed with pure 

 water. The coloring was uniform and decided, and in many of the cells the 

 Streaming was scarcely impaired. In both this species and T. Virginica the 

 cells in the neighborhood of the fibro-vascular bundles are the best as they 

 contain almost no granulär Contents, and the protoplasm is reduced to a 

 thin layer close to the wall so that the nucleus lies perfectly free. 



Tradescantia zebrina. 



The stamen-hairs of this species were not investigated, but the root- 

 hairs were found to afford a very convenient and useful object. 



In Order to obtain good material, pieces of the slem were removed from 

 the earth and placed in a vessel of rain-water. Here in the course of a few 

 days roots are abundantly developed at the nodes and the voot-hairs with 

 which they are densely covered show good protoplasmic Streaming and the 

 nuclei are well-defined. 



In Order to color the nucleus it is only necessary to plunge the root 

 with its attached root-hairs for about half a minute in a -002 ^ Solution of 

 any of the three colors mentioned. This is enough to give an evident, though 

 not very deep stain, and at the same time does not stop the Streaming of 

 the protoplasm. The protoplasm is also somewhat colored, but as the nu- 



