286 BOTANICAL GAZETTE. | December, 
the original tripartite nature. When treated with a mixture 
of half water and glycerine the nuclei are easily seen. On 
the right of # are three grains; the upper one shows an end : 
view with the three division lines of the grain. Below this | 
are two grains in which the nuclei are evident. ‘There seems 
to be a nucleus for each third of the grain. After pollen has 
been in pure glycerine for two days the grains become plump 
and the contents are nearly colorless, except the nuclei, 
which are large and well defined. Three such grains are 
shown at c. In many instances the nuclei seemed unite 
by their ends, while in others all three were evident. 
For germination fresh pollen was placed in a ten per cent. 
solution of cane sugar in one of a nest of porcelain macerat- 
ing dishes, and forty hours after the tubes were of the 
lengths indicated in the plate. The earlier stages of gel 
mination are shown at d. Usually there was a single tube, 
but occasionally the tube branched as it issued from the 
grain. In some cases there were two points of departure, RP 
shown near @ and at 4. The course of the tube was rarely 
in a straight line, but instead became much twisted and con- 
torted during the early part of its growth. Afterwards it 
expanded into a swollen tip as at e, where there is a strong 
tendency to fork at its enlarged extremity. To the left of 
is a tube which makes a sharp twist near the middle and aft- 
erwards swells into an Indian-club-like tip. 
The coloring substances which proved the best be the 
were drawn from eosin-prepared specimens. f 
methyl green recommended by Dr. Strasburger proves 58 
very little service in comparison with the azo-rubin. oe 
latter substance almost instantly developed a deep bloee 
color in the nucleus, while the remaining portion of the eit 
toplasm was left of a lighter hue. eh fresh 
/bservations were repeated from day to day ie of 
specimens dipped from the culture dish, and the presence In 
the three nuclei was demonstrated in hundreds of cases- uld 
fact, in nearly all long tubes the three blood-red bodies We ny 
appear upon the application of the coloring reagent. a east 
imstances the three nearly equal-sized bodies were fo 
after all else in the tube had disappeared. 
