26 ARTHUR BOLLES LEE 
few more. So here we have about twenty-four staves, repre- 
senting forty-eight limbs. Or take fig. 38, also a completed 
clump. It shows twenty-one staves, and may contaim a very 
few more. ‘Therefore here again about twenty-four staves for 
forty-eight origmal limbs. Now take fig. 31, a nearly com- 
pleted clump from Bombinator igneus. The diploid 
number of chromosomes in this species is sixteen, showing 
therefore thirty-two limbs at the anaphase. The clump con- 
tains twenty staves. Therefore not all of these can represent 
limbs of V’s; but twelve of them probably represent twelve 
whole V’s, and the remaining eight represent single limbs of 
such ; total, thirty-two. 
It is therefore certain that in any polar clump some of the 
staves—and highly probable that in the completed clump all of 
the staves—must represent each of them two limbs of 
a V. And the conclusion follows, that each of those of the 
completed clump is in fact a V whose limbs have folded together. 
So that the observed duplicity of the staves is not due to the 
chromosomes having undergone a cleavage after having in some 
other way assumed the shape of staves, but to their consisting 
of the two limbs of an anaphase V—or what remains of these. 
For the folding fully accounts for the duplicity. 
In the Amphibia the postulated folding of the V’s takes place 
as a rule only during the formation of the polar clump, not 
before. But exceptionally it may take place during the early 
anaphase. Vig. 41s a case in pomt. In this anaphase the limbs 
of the V’s are in several instances closed in to a distance of only 
about half a micron (as measured by the drumhead of the fine- 
adjustment), and so accurately superposed on radu of the figure 
that it is only by the most careful attention that the elements 
can be seen to consist of two superposed moieties. 
But this, which in the Amphibia seems to be the exception, is 
in some other animal groups the invariable rule. For instance, 
in the spermatogonia of the Acridian Oedipoda cothurna 
(Arcyoptera variegata) I invariably find the state 
of things represented in fig. 61. This is a sagittal section of 
a mid-anaphase, the chromosomes being not yet half-way to the 
