On Chromatin Extrusion in Pollen Mother-cells of 
Lilium candidum, Linn. 
BY 
CYRIL WEST, B.Sc. 
AND 
ARTHUR ECKLEY LECHMERE, D. is Sc. (Paris). 
With Plate XV. 
T HE improved technique of modern cytological research has revealed 
many interesting nuclear phenomena, one of the most significant 
of which is the process of ‘ chromatin ’ extrusion from the nucleus of one 
pollen mother-cell into the cytoplasm of an adjacent cell during various 
stages in the heterotype division. Although this condition had previously 
been noticed by several botanists, no importance was attached to it before 
1909, in which year Miss Digby published a very complete account of the 
extrusion of 4 chromatin 5 bodies from the pollen mother-cells of Galtonia 
candicans ( 4 ). In every respect the cells in this plant appeared to be quite 
normal, while the fixation was perfect. In two more recent papers 
the same author (Digby ( 5 , 6)) calls attention to a similar protrusion 
of ‘ chromatin’ into adjacent mother-cells of anthers of Crepis taraxacifolia 
and Primula kewensis (type) respectively. 
In the course of his investigations on the cytology of various races 
of Oenothera , Gates (10) discovered and gave a full description of a process 
of ‘ chromatin ’ extrusion during the synaptic stages of the pollen mother- 
cells of Oenothera gig as and of Oenothera biennis , the extrusion taking 
place along definite cytoplasmic connexions between adjacent mother- 
cells. Describing the subsequent behaviour of the extruded material, this 
author (1. c., p. 935) states that ‘ the extruded chromatin accumulates in 
a mass after passing through the cell-wall. A clear liquid appears around 
these masses, and a membrane delimits the clear area from the cytoplasm, 
forming what I have called a pseudo-nucleus. Later, these masses loosen 
up, and acquire an appearance very similar to a spireme. The membrane 
afterwards disappears and the extruded chromatin finally appears to be 
[Annals of Botany, Vol. XXIX. No. CXIV. April, 1915.] 
