CYTOPLASMIC INCLUSIONS OF THE GERM-CELLS. 425 
with their neighbours, and also become elongated in the 
same direction. In PI. 23, fig. 10, this is clearly shown, and 
in extreme cases the mitochondria form threads, as in PI. 25, 
fig. 31, elongated in the same direction as the spindle ; this 
takes place especially in the anaphase and telophase. 
In PI. 25, figs. 32, 33, and 34, some stages are shown in 
which the mitochondria are blacked in for clearness. PI. 25, 
fig. 32, was drawn after focussing on the cell till only 
the outer layer of mitochondrial bodies were in the field ; 
by screwing the microscope tube further down one focussed 
upon the spindle and chromosomes, as in PI. 23, fig. 10; 
only in the latter the bodies are grouped to one side 
of the daughter cells. PI. 25, fig. 33, is drawn from such 
a section as that through X. — X. in PI. 25, fig. 32. The 
clumped chromosomes are seen in the middle, and it will be 
clear from these two drawings that the mitochondria often 
form two funnel-like masses with their narrow ends applied 
to each other, representing the region where the cells con- 
strict. In PI. 25, fig. 32, the elongation of the mitochondrial 
bodies is evident ; the figure suggests that such elongation 
might be due to mere mechanical reasons, pressing of the 
individual mitochondria one against the other. 
In PI. 25, fig. 34, a second maturation division is shown, and 
the tendency to a running together of the bodies is noticeable. 
In both maturation divisions the behaviour of the mito- 
chondria is similar, only in the second one the latter tend to 
run together more. In PI. 25, fig. 27, I have drawn a first 
maturation metaphase of Orgyia anti qua to show the hap- 
hazard arrangement of the mitochondria and their inde- 
pendence of the spindle. 
The newly-formed spermatid is^a cell like that drawn in 
PI. 23, figs. 13 and 14, the mitochondria* rarely surrounding 
the nucleus, but being heaped to one side of the cell. In 
neither of these cases had the mitochondria run together at 
all. The mitochondrial bodies now proceed to form the macro- 
mitosomal spireme as follows : 
