736 Digby.—The Somatic , Premeiotic , and 
not only between nucleus and nucleus, but within the individual nucleus 
itself. The somatic division figures of Galtonia can neither be adequately 
illustrated by diagrams nor described ‘ by a rule of thumb 
II. First Meiotic Division. 
It has already been said that the archesporial divisions have been 
studied in order to watch the transition of the telophase of the last 
archesporial division into the early prophase of the pollen mother-cell. 
In this way a genuine comparison between the premeiotic and meiotic 
divisions can be obtained. 
It is extremely difficult, if not impossible, to assert positively that any 
one particular telophase is that of the last archesporial division ; and as a 
necessary outcome that its two component nuclei will become pollen mother- 
cells. The archesporial nuclei in Galtonia do not divide synchronously. 
In a section of an anther before the differentiation of the pollen mother-cells, 
the archesporial nuclei are at all stages of division. These nuclei pass 
imperceptibly into the pollen mother-nuclei. There is no rest between the 
last stages of the archesporium and the differentiated pollen mother-cells, as 
is also the case in Hyacinthns orientalis ( 13 ). In the anthers of the very 
youngest buds that undoubtedly show pollen mother-cells, the majority of 
the nuclei will be seen to be in the very early prophase, whilst others have 
apparently only just divided and are still in telophase, and others again 
may be yet in late anaphase. No dividing line can be drawn between these 
stages. The nucleus proceeds, without interruption, on its course, and it is 
only by its general appearance that it becomes evident that it has passed 
through one phase and has entered upon the next. 
Immediately on the differentiation of the pollen mother-cells, the anther 
increases in size. The cells therefore cover a larger area, and consequently 
the nuclei become more widely separated. In very young buds the pollen 
mother-cells of the inner whorl of anthers will be still small and closely 
packed together, having only just divided, while those of the outer whorl of 
anthers will already show a great increase in size both in cells and in nuclei. 
It is from these very young pollen mother-cells that the telophases have 
been taken as those of the last archesporial divisions. 
Telophase of the last Archesporial Division. 
Except for the fact that the nucleus is slightly larger in size, the 
telophase of the last archesporial division resembles in detail that of the 
somatic divisions (PI. LX, Fig. 30). The chromosomes fragment transversely 
into portions of linin. There is much vacuolization in the chromosome 
portions, and much parallelism in the thin threads resulting from the 
vacuolization of the chromosomes. As in the somatic divisions fine con- 
