Meiotic Divisions in the Microspore Mother-cells of 
Smilacina racemosa (L.), Desf. 
BY 
RUTH WOOLERY, 
Indiana University , Bloomington, Indiana. 
With Plate XXII and one Figure in the Text. 
B ECAUSE of some remarkable statements made by Lawson (’ll a) con¬ 
cerning ‘The Phase of the Nucleus known as Synapsis’, material was 
collected and work on this paper was begun. Cytology has for many years 
had many questions of dispute among its investigators, but it is only through 
continued investigation that the whole truth can be known. As has been 
found, Smilacina racemosa offers a favourable plant for study, as the flowers 
are borne in rather small, compact racemes, and several stages in the division 
of the microspore mother-cells may be found in one flower cluster, the older 
ones being at the base and the younger at the apex. McAllister (T 3 ) used 
this plant for his study, but the species of Smilacina used by Lawson (’ll A 
and T2) was not indicated. 
Material and Method. 
Materials for this investigation were collected from the west side of 
a deep ravine north-east of Bloomington, Indiana, in the latter part of April 
and first of May in the years 1912 and 1913. The strong chrom-acetic 
solution and the stronger Flemming’s chrom-osmic-acetic solutions were 
used in fixing the material. Whole racemes, or portions of racemes, were 
embedded in paraffin, and sections were prepared varying in thickness from 
5 to 15 microns. Preparations were stained in Haidenhain’s iron-alum- 
haematoxylin and in the regular triple stain, using orange G in aqueous 
solution or as a saturated solution in clove oil. Especially good prepara¬ 
tions, showing metaphase and closely-related phases, were secured by using 
on material fixed in chrom-acetic a solution of gentian violet and clove oil, 
as suggested in the laboratory by F. L. Pickett. 1 
1 A supersaturated solution of gentian violet in clove oil is prepared by adding to a saturated 
solution of the stain in absolute alcohol an equal volume of clove oil and allowing the mixture to 
stand in an open dish at room temperature until all the alcohol has evaporated. The resulting 
solution is then filtered through paper. After the safranin has been washed from the sections 
[Annals of Botany, Vol. XXIX. No. CXVI. October, 1915.] 
