1088 
1000 or less of methyleneblue, the pigment penetrates through the 
seed coat into the germ, which partly colours blue. The germroot 
takes up the colour the earliest; then follows a triangular field on 
the outer of the two seedlobes, which lie folded up in the seed. 
The base of the triangle, which colours first and most intensely, lies 
at that margin of the cotyledo, which is turned towards the germroot. 
Obviously the pigment has very quickly penetrated through the 
micropyle of the seed, and only later through the seed coat. With 
stronger methyleneblue solutions the experiments do not succeed 
much better, because then the pigment accumulates so much in the 
seed coat, that even water can only enter with difficulty. After 24 hours 
such seeds are but imperfectly swollen but, somewhat later, the 
germination takes place as well. The coloured germs swell at 30° C. 
so vigorously, that many soon burst out of the seed coat. When the 
partly blue germs, freed from the seed coat, germinate on filterpaper, 
they yield part of their pigment to it, but especially in the meristem 
of the germroot it continues to show for several days and disappears 
only at length, by the dilution which accompanies the growth. It is 
then easy to see how the part near the rootmeristem grows the most 
rapidly whilst the region of the roothairs grows no more at all. 
That the pigment, without killing the cells, has penetrated into the 
‘inner part of the tissues, is not only shown by the germroots, but 
also by the coloured spots of the seedlobes, whose phloembundles 
even have taken up the colour. 
Botany. — “On Karyokinesis in Eunotia major Rabenh”. By 
Prof. C. van WisserinGH. (Communicated by Prof. Morr). 
(Communicated in the meeting of November 30, 1912). 
LavTeRBorN’s') detailed investigation on Diatomaceae suddenly 
brought about in 1896 a complete change in our knowledge of the 
karyokinesis of these organisms. This investigator studied the process 
in Surirella calcarata, Nitzschia sigmoidea, Pleurosigma attenuatum, 
Pinnularia oblonga, and Pinnularia viridis. He came to the conclusion 
that the nuclei always divide karyokinetically. The karyokinesis here 
is not less complex than in higher plants. [t shows an important 
deviation. For LACTERBORN found that in all cases during karyoki- 
1) R. Lavrersorn, Untersuchungen über Bau, Kernteilang und Bewegung der 
Diatomeen, 1896. 
