1886. ] BOTANICAL GAZETTE. 13 
figure 13. Oy the size of the generative nucleus it was 
hoped that its division could be demonstrated, but such was not 
the case. Although in some instances it was suspected, it was 
not clear enough to be certain. 
After the generative nucleus had entered the tube, the nucleus 
of the vegetative cell seemed to be carried forwards, and when 
the former had proceeded some distance down the tube, the latter 
was swept into it, and followed along at considerable interval 
(figures 10, 11,12, 13). The vegetative nucleus retained its struc- 
ture perfectly as far as we were able to trace it in the cultures. 
The nuclei in the spores could always be demonstrated after a 
short immersion in the sugar solution, without the use of a stain- 
ing fluid, but of course were brought out much more distinctly 
by it. The nuclei in the pollen-tubes, however, were never seen, 
with certainty, without staining. e method employed was as 
follows : drop each of magenta solution and ordinary acetic 
acid was placed upon a slide, the cover-slip with hanging drop 
of sugar solution containing the developing pollen-tubes was let 
down into it, and then, after a moment or two, glycerine was run 
under.” In this way the nuclei in the tubes receive a dark stain, 
while the intine is left colorless. Of course there are other and 
better methods and stains, but our ebject was to use only such 
reagents as could be obtained at any drug store. Crushing a 
Stained pollen-spore resulted as shown in figure 17, by which 
method the shape and structure of the nuclei can easily be studied. 
It should be said that in many cases both nuclei were not visible, 
as is represented in figures 14 and 15, although this fact should 
not be connected with the spores that are exceptional in other re- 
spects. In many instances a tube began to develop from each end 
of the pollen-spore, as shown in figure 15, but one was usually 
Stronger than the other. Quite frequently a pollen-tube devel- 
oped from one side instead of the end, as represented in figure 14. 
These two cases would seem to indicate more than one point of 
emergence, contrary to the general rule among monocotyledons.” 
®*Sachs, Text-book, 2d English ed., p.583; Strasburger, Neue Unt hungen, p. 15 
1° Or the magenta and acetic acid were added directly to the culture drop, allowed to 
Standa moment, and then inverted and mounted in a drop of glycerine, 
"Sachs, Text-book, 2d English ed., p. 555. 
