THE MEIOTIC PHENOMENA IN BLAPS 9] 
clearly. In figure 80 a portion of the M-chromosomes has been 
cut by the knife, the X-chromosome appearing separated from 
the former. These relations are preserved in figure 79. 
A little later the M-chromosomes become shorter, and corre- 
spondingly thicker. Assuming that parasynapsis occurs in these 
chromosomes, we ought to find some cells in which a single thick 
thread is connected with the X-chromosome, but careful search 
failed to reveal such a condition, the relations just described oc- 
curring in hundreds of cells. Occasionally the M-chromosomes 
are not visible, being entangled in the mass of euchromosomes, 
but wherever they appear one can be sure that they are separated. 
During the pachytene stage proper the complex stands out quite 
sharply within the nucleus. It is possible to detect the relations 
of the M-chromosomes and the accessory in almost every cell, 
and in many complexes the small chromosomes are united with 
the accessory. Perhaps the clearest case of this is represented 
in figure 26 of my first paper, in which this relation was thought 
to be accidental. 
At this time two varieties of complexes are found. In one the 
X-chromosome is situated between the two M-chromosomes (figs. 
82, 83, and 84) which are often united by the opposite ends by a 
very thin thread. In the other kind, already represented in the 
paper just mentioned, the X-chromosome is at the extremity of 
one of the M-chromosomes, which are directly united with each 
other. I do not believe that the last arrangement is accidental, 
for similar complexes occur rather often during this stage as well 
as during the prophase and metaphase of the first maturation 
division. That the M-chromosomes are united directly by one 
of their ends is obvious, for the length of the single thread thus 
formed is approximately twice that of each M-chromosome (figs. 
81, 85, and 86). 
It is interesting to note that the length of the M-chromosomes 
is sometimes unequal. Thus in figure 84 the thread at the right 
is shorter, as shown by the break in outline which marks the distal 
ends of both M-chromosomes, connected here by a thread. No 
small chromosomes were visible in this case. It is quite possible 
that such inequality is due to the interpolation of the latter be- 
