ij 6 Trow.— Observations on the Biology and 
clearest view obtained. At the poles of the spindle there 
were four small granules ; two threads of the achromatic 
spindle could be traced from pole to pole, and to end in these 
granules ; but no other threads were clearly seen. In the 
equator were two chromosomes which probably concealed 
two others, as there were indications of three in Fig. 38, and 
of four or five in Fig. 37. At this stage the nuclear membrane 
is still intact and the kinoplasm may occupy a lateral position. 
Fig. 39 represents a small portion of an oogonium in which 
the nucleus is in the diaster stage. The nuclear membrane 
still persists here, there are two pairs of daughter chromosomes 
and the threads of the spindle are seen to converge to one 
pole, but pursue a parallel course towards the other. Fig. 40 
represents an end view of a similar nucleus. 
Careful consideration of these figures and a large number 
of others, led to the conviction that in Achlya the achromatic 
figure is derived from the linin-network within the nucleus, 
as the nuclear membrane persists at any rate up to the diaster 
stage and there is no indication of the insertion of threads 
from the exterior. With such difficult objects of study it 
was impossible to obtain better results. It may be regarded, 
however, as proved that many, if not all of the nuclei in the 
oogonia and antheridia divide by an indirect method during 
the development of the gametes, and that the number of 
chromosomes in the nucleus is in all probability four, possibly 
varying between four and five. 
Now comes the really difficult part of the study. Dis- 
missing from the mind all preconceived ideas as to what 
ought to take place, bearing in mind — to anticipate a little — 
that each egg, when first recognizable as such, possesses one 
nucleus, we have to ascertain the fate of the supernumerary 
nuclei. A glance at the figures shows that many more 
nuclei are enclosed in the oogonia than are sufficient to pro- 
vide one for each oosphere ; countings of eggs on the one 
hand and nuclei on the other, show that on the average the 
number of the nuclei in an oogonium is ten times greater 
than the number of eggs to be produced. 
