Quarterly Journal of Microscopical Science, Vol s2-78, 303-309, Copyright © 1935 by Company of Biologists

Memoirs: Note on the Behaviour of certain Cell Inclusions during Mitosis in Tenthredinidae

¹ University College, University of St. Andrews, Dundee

1. Four conspicuous rounded bodies, lying symmetrically disposed, one on the surface of each quadrant of the spindle,have been found during the metaphase of blastoderm cells developed from the partheno-produced (male) eggs of Thrinax mixta, a parthenogenetically arrhenotokous species of Tenthredinidae.

2. During the process of cell division they ultimately form a single mass in a position formerly occupied by the centre of the spindle, and the material composing this mass streams out towards either pole and appears to be more or less equally shared between the two daughter cells. The movements of the inclusions appear to be due to changes in the form of the spindle.

3. Their fate is unknown, as is their function.

4. Such bodies and their behaviour do not appear to have been recorded before, but in certain respects they behave like aggregations of thread-like cell inclusions in Stenobothruslineatus which Bêlaê calls mitochondria; that they are mitochondrial is suggested from the technique which revealed them.

5. It is suggested that such bodies might easily be mistaken for sex chromosomes