The.Staining of living Nuclei. 579 



sections of the root must be made. With stronger Solutions, even when 

 the protoplasm is nol killed, the cell-wall is often slained very intensely 

 which of course interferes seriously with the study of the nucleus. 



Hyoscyamus niger L. 



The stamen-hairs of Hyoscyamus afford a fairly good subjeet for our 

 purpose. The stamens should be stripped away from the corolla taking 

 care to remove with them as many hairs as possible, and the stamens with 

 the attached hairs then plunged in the staining fluid. With a -01 ^ mauvein 

 Solution the nucleus in a number of cases was colored in two hours with 

 distinet protoplasmie Streaming. With a -005^ Solution of the same the 

 results were not good, but with a similar Solution of dahlia, after remaining 

 all night, some good examples were found. 



Campanida spec. 



The bases of the filaments of the different species of Campanula are 

 provided with hairs much like those of Asphodelus albus. Owing to the 

 very active Streaming and the large nucleus, it was hoped that these would 

 prove favorable subjects, but unfortunately the cuticle is so thick as to ab- 

 solutely prevent the absorption of the coloring agents in the great majority 

 of cases. 



The first species studied, C. latifolia L., gave occasionally good re- 

 sults. The stamens were left over night in -001^ and -OGOö^ Solutions 

 of mauvein and dahlia, and in both cases colored nuclei were found. The 

 best color was had with the stronger Solutions, but the Streaming was not 

 so well marked as in those cells that were treated with the weaker, in 

 which the nucleus was also pretty well colored. 



Stamens of C. medium and C.persicifolia, placed in the same Solutions, 

 gave negative results. 



The hairs are thinner-walled in C. rotundifolia and a rather larger pro- 

 portion are colored than with C. latifolia, but as will Ihis species, the co- 

 loring is very uncertain. With both species it was sometimes impossible to 

 get any stain without killing the cells, the color often not being taken up 

 at all. 



Later experiments with stronger Solutions of dahlia and mauvein gave 

 similar results; possibly a little better, but not remarkably good. 



Adenophora latifolia. Fisch. 



This plant is closely related to Campanula j and has similar stamen- 

 hairs. The cuticle of these hairs is, however, thinner, and the cells take 

 up the color somewhat better. Stamens left over night in -002^ dahlia and 

 mauvein Solutions were found in the latter case to have some of the nuclei 

 colored. The nucleus was very well colored in these, and the movement of 



Untersuchungen aus dorn botan. Institut in Tübingen. Bd. II. 38 



