290 West and Lechmere.—On Chromatin Extrusion in 
very active during the various phases leading up to and concerned with the 
reduction division. Many interesting cases of ‘ chromatin ’ extrusion into 
the cytoplasm of the same cell have recently been recorded. This con¬ 
dition appears to be widespread amongst both animals and plants. It has 
been observed in a number of plants by von Derschau ( 2 , 3 ), 1 in various 
Ferns by Farmer and Digby ( 7 ), in Crepis virens by Digby (6), and in 
Helvetia by Carruthers ( 1 ), whilst the peculiar process of nuclear gemmation 
observed by Griggs (12) in Synchytrium exhibits many features in common 
with the above. 
We are not yet in a position to decide whether the cases cited above 
bear any relation to the phenomena described for Lilium candidum ; it is 
therefore advisable to leave it an open question as to whether they should 
come under the same category. 
Amongst the lower animals, especially the Protozoa, an elimination of 
nuclear material has been observed and described by many authors. Here 
again the phenomena observed probably represent an excretion of waste 
products from the nucleus, and are no doubt analogous with the processes 
described above. 
The condition of excessive ‘ chromatin ’ extrusion found in two anthers 
of Lilium candidum suggests the degeneration of the mother-cells, and 
consequently the abortion of the pollen grains ; against this it can be urged 
that although a large number of anthers showing later stages in the 
development of the pollen were examined, not one of these presented the 
appearances usually associated with pollen sterility. 
Summary. 
1. A process of ‘chromatin’ extrusion from pollen mother-cell nuclei 
into the cytoplasm of adjacent mother-cells is described for Lilium 
candidum. 
1. This process takes place during the synaptic and c hollow spireme ’ 
stages. 
3. The nucleolus takes no part in the extrusion. 
4. The authors regard this phenomenon as a normal condition of 
meiosis, the extrusion of nuclear material (i.e. waste products) being 
attributed to the active metabolism of the nucleus during the meiotic 
phase. 
In conclusion we desire to express our thanks to Professor J. Bretland 
Farmer, F.R.S., for much helpful advice and criticism throughout the 
course of this investigation. 
1 A further list of references can be found in these papers. 
