283 
Till . — Some Details of the First Nuclear Division in the Pollen- 
Mother-Cells of Lilium Martagon L. 
By Ethel Sargant. 
Communicated by I). H. Scott, Ph.D., F.R.S., F.R.M.S. 
{Read 15 th May , 1895.) 
Two observers have recently called attention to the manner in which 
the segments of a single chromosome separate from each other 
during the first division of the nucleus in certain pollen-mother-cells.* 
The agreement of these independent researches is very striking. 
Having some preparations of the stages in question from anthers of 
Lilium Martagon , as well as a stock of good material, I have made 
some observations on the subject, and since my results differ some- 
what from those just mentioned, it seems desirable to publish a short 
account of them. 
All the details which follow refer to anthers of Lilium Martagon 
fixed last summer in Hermann’s solution, chromic acid, or absolute 
alcohol. After proper hardening, they were preserved in a mixture 
of alcohol, glycerin, and water. Most of the observations have been 
made on microtome sections of 5-15 pu in thickness, but these have 
been compared with hand sections from alcohol material. The 
sections were stained in various ways : on the whole, for Hermann or 
chromic material I prefer Henneguy’s safranin or Flemming’s orange 
method, t and for thick sections of alcohol material a mixture of 
methyl-green and acid fuchsin. 
When the nuclear plate is first formed, each chromosome has 
been for some time completely divided by a longitudinal fission.J 
The segments lie side by side, and the fission is seen as a dark line, 
except at one end, where the segments have begun to separate (fig. 42). 
This is the end nearer the axis of the spindle, and it is attached to 
a sheaf of spindle fibres sp. 
The chromosome itself is straight, and its segments are therefore 
straight too, except for the bend where they have begun to separate, 
and for any irregular curves where they do not adhere closely (fig. 42). 
In the typical diaster stage the segments are completely separated, 
and are arranged in two groups on the way to the poles, but they are 
* J. B. Farmer, “ Ueber Kerntheilung in Lilium-Antheren besonders in Bezug 
auf die Centrosomen-Frage,” Flora, 1895, Heft i. [Pollen-mother-cells of Lilium 
Martagon , candidum, speciosum, tigrinum.~\ W. L. Belajeff, “ Zur Kenntniss der 
Karyokinese bei den Pflanzen,” Flora, Erganzungsband, 1894. [Pollen-mother- 
cells of species of Larix, Lilium, and Fritillaria.'] 
f For details of these processes see Bolles Lee, ‘ Microtomist’s Vade-Mecum, 
3rd English edition, pp. 70 and 160. Before using Flemming’s method I usually leave 
the sections for 10-15 minutes in a 1 per cent solution of permanganate of potash, 
afterwards clearing with clove oil. 
X L. Guignard, ‘Nouvelles Etudes sur la Fecondation,’ p. 175. 
