heterochromosome

Figures 72-74 show the metakinesis of the heterochromosome bivalent.

The heterochromosome group is blended into a vacuolated sphere in growth stages (figs. 199, 200).

Figure 137 is an exceptional anaphase in which the heterochromosome elements are not mingled with the polar masses of chromatin.

Bouquet stage from iron-hæmatoxylin preparations, showing the heterochromosome bivalent (x).

Of the insects considered in this paper Aphis and Termopsis have no "accessory chromosome" or "heterochromosome" of any kind.