16 ARTHUR BOLLES LEE 
interphase it is seldom possible to detect even a vestige of them 
with certainty. 
As to the sheath at this stage, the appearances are similar. 
In the nucleus of fig. 47 (Bombinator) (which shows one 
half of a rig such as that of fig. 50), Lam not able to see it, 
except (possibly) on the chromosome at the extreme left. In the 
nucleus of fig. 48, a later stage, also Bombinator, I have 
not been able to detect it. In that of fig. 49 (Triton) I think 
I can see it in the two places marked with a cross, and glimpse 
it in one or two others. In that of fig. 50 (Salamandra) 
I have been able to see it in a fragmentary way in half a dozen 
places, as marked. In that of fig. 51 (Triton, follicle nucleus 
of testis) I have been able to detect it in only three places 
(also marked). It is certamly less abundantly evident in these 
nuclei than in the earlier stages. And this can hardly be 
accounted for by greater difficulties in the way of observation ; 
for the chromosomes are now more widely spaced than before, 
and observation of their edges should therefore be easier. Add 
to this that the sheath when detected can only be made out 
in a fragmentary way; can only be followed for very short 
distances ; 1s less regular than in earlier stages, being frequently 
distinctly dilated ; and can in some places be seen distinctly to 
be ruptured (details which it is not possible to render satis- 
factorily in a drawing). It may be stated as certain that 
towards the end of the telophase the sheath has generally to 
a great extent disappeared. And this disappearance seems to be 
due to a process of real disintegration ending in destruction, 
rather than to a mere change of configuration or relation of 
parts. For in completely ‘resting’ nuclei, even if these are 
such as to offer every facility for observation, not a trace of it 
can be detected. 
The periaxial spirals and sheath thus lost to view at the 
telophase come into view again gradually at the next prophase. 
In the earliest stages im which the spireme is recognizable as 
being indubitably such (figs. 24 and 25) it seems to consist 
merely of tortuous naked threads (often clearly double, same 
figs., and especially fig. 25). These may be united by inter- 
