Nuclear Division in Funkia. 
385 
The single spireme now becomes mucli stretched and elongated 
and is uniformly distributed throughout tbe whole nuclear cavity. 
Fig. 34. PI. VIII represents a very tbin section of tbis stage, the cut 
ends being all in the plane of tbe section. Tbe continuous, single, 
tbin spireme does not seem to be of long duration and indications 
of fission soon appear in various parts of tbe thread; a double ap- 
pearance is already indicated in various regions in Fig. 34. A double 
continuous uniformly distributed spireme is however never found and 
it is therefore certain tbat tbe fission does not extend along tbe whole 
length of tbe spireme before Segmentation begins. Tbe absence of 
a double loose spireme is also of great significance in connection 
with the seriation of the stages. Siuce all tbe double spiremes show 
more or less evident signs of synaptic contraction, tbe fusing spiremes 
very little and tbe single spiremes no signs of tbis, there can be no 
doubt of the Order of these stages, *) and therefore no doubt tbat 
the double spireme gives rise to the single by the fusion of its two 
component threads. 
I was quite unable to find in tbis series anything of tbe nature 
of a definite second contraction such as tbat described in otber plants 
by several authors. 1 2 ) 
IV. Segmentation of tbe spireme. It bas been said tbat 
simultaneously with the Splitting of tbe spireme, wliich takes place 
presumably along the line of previous fusion, Segmentation occurs. 
Sometimes the fission is more or less visible throughout tbe length 
of the spireme, while Segmentation bas only occurred in one or two 
places, (Fig. 35. PI. VIII.); in otber cases tbe single spireme dividesinto 
many straigbt single lengths, (Fig. 38. PL VIII.), in which however, a 
double row of chromomeres is generally found. Sometimes tbe pieces 
formed are more or less looped or coiled, as seen in Figs. 36 & 37. 
PI. VIII, in the former of which a nucleus is shown in which part of 
the spireme is still single, while in otber places both granules and 
liuin liave split. 
In a very few cases the spireme is thrown into regulär loops 
arranged round tbe nucleolus, but no definite number of loops seems 
to be prevalent although there are generally fewer than twenty-four; 
it seems improbable tbat in Funkia tbis stage has any special signi- 
ficance. Overton and Allen bave described loops eacb of which 
1 ) See also P. 3. 
2 ) Farmer and Moore. 1905. Fraser. B. A. Leicester. 1907. 
