82 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 
Instead of considering that we have here a regular revolution of the 
nucleus, it seems to me more reasonable to suppose the variation in 
the position of the point of attachment in the earlier stages to be due 
to the mutual pressure of surrounding cells. ‘The interzonal body, 
which is the criterion used to distinguish the distal pole, invariably 
lies in the part of the cell containing the greatest amount of cytoplasm, 
and the shape of any cell is certainly largely determined by the pres- 
sure of surrounding cells. It would, therefore, seem only reasonable 
to suppose that the relative positions of the nucleus and interzonal 
body might be considerably influenced in this way. ‘The revolution 
of the nucleus in some cases would, then, be simply a readjustment 
in the cell to a more or less definitely fixed polarity which had been 
temporarily lost. 
In the following stage (e) the chromatin granules (Plate 2, Fig. 34), 
which are distributed along the spireme threads, divide so that each 
loop shows more or less distinctly a longitudinal split. It should be 
clearly understood that this splitting does not extend to the linin, which 
now forms a flattened ribbon like structure, in which the paired chro- 
matin granules are imbedded. This stage undoubtedly corresponds 
to the split spireme of authors. I believe this double series of chro- 
matin granules to be formed by the splitting of the single series of 
granules of the preceding stage, rather than by a side to side union of 
two distinct threads, as has been held by a number of recent writers 
to be the case in other forms. Long and careful study of a large num- 
ber of cells in this and preceding stages has convinced me that there 
is little evidence in this species (or in other Orthoptera) of a side to side 
union of the spireme-threads. Occasionally during the preceding 
stage two threads can be seen lying parallel for a short distance, but 
if carefully followed they can in almost all cases be seen to diverge 
again. This, combined with the fact that such structures are com- 
paratively rare, has convinced me that they are only accidental. More- 
over, in stage e part of the chromatin granules along a given thread 
may be single while others are double.- The single granules are 
usually elongated transversely to the thread as though preparing to 
divide into two. Of course it may be argued that these granules are 
formed by the fusion of two originally distinct granules, but there is 
little to support such an interpretation, since there is no evidence that 
the longitudinal split later becomes obliterated by the fusion of the 
halves. However, the whole question will be taken up later, in a dis- 
cussion of the literature, where it can be considered to greater ad- 
vantage. During stage e the polar arrangement of the spireme is 
