32 BOTANICAL GAZETTE [JULY — 
and by Davis (7) for Pedlia epiphylla. Unfortunately, no material 
of Pallavicinia in this stage was available, but the striking resem- 
blance of Farmer’s (8) figures to the mitoses in deeply lobed 
mother-cells of other Jungermanniales leads us to suggest, as 
Davis (7) has already done, that Farmer (8) may have misin- 
terpreted the quadripolar figure in this genus. 
THE GERMINATING SPORE. 
The first, second, and third mitoses in the germinating spore 
of Pellia cannot be regarded as distinct types, for with diligent 
searching one could select a series of mitoses at the second 
division, or even at the third, which would be identical with a 
series at the first division. In fact, we have used figs. 7, 8, and 
rg of the third mitosis to illustrate also the same stages in the 
first and second mitoses. Nevertheless, it is true that, in a great 
majority of cases, kinoplasmic activity is most energetic during 
the first division, and that in succeeding divisions it becomes less 
and less conspicuous, until centrospheres and asters cease io 
attract any attention, and it finally becomes doubtful whether 
they are present. 
THE FIRST MITOSIS IN THE GERMINATING SPORE. 
As the nucleus of the germinating spore increases in size pre- 
paratory to the first division, the area immediately surrounding 
it becomes comparatively free from starch grains and coarser 
granules (plate X//, fig. 1). It seems reasonable to suggest that 
some substance, escaping from the nucleus into the cytoplasm, 
causes this zone and acts as a stimulus to the formation of the 
extra-nuclear portions of the achromatic figure. It is not impos- 
sible that such a substance might actually take the form of a 
centrosphere. (The origin of the aster will be considered when 
dealing with the second division.) After the spirem has become 
segmented into chromosomes the nucleus elongates and the 
nucleolus appears very much vacuolated (jig. 2). At this stage 
a pair of dome-shaped caps (figs. 3, 4) may be recognized at 
opposite poles of the nucleus. These caps, which will be con- 
sidered later, appear in transverse section as a delicate ring, but 
a similar section of the completed spindle shows a dense mass of 
fibers (fig. 5). 
