154 
Proceedings of the Royal Society of Edinburgh. [Sess. 
rapidly by mitotic division, as in somatic cells. The superficial row of cells 
are larger and more spherical, “ protobroque (a),” the remaining cells being 
smaller “protobroque (6).” The protobroque (a) cells divide and form 
similar cells which go to form the superficial layer on the ovary with its 
subsequent invaginations. The protobroque ( b ) cells form new oogonia, 
some of which become oocytes, others follicle cells. The author traces the 
changes which take place in the nucleus of the oocyte when it becomes 
larger, spherical, and clear, the chromatin spreading out as a fine reticulum, 
with a nucleolus and well-defined nuclear membrane “ deutobroque ” cells. 
Mitosis occurs in the protobroque cells, but ceases in the deutobroque variety. 
The chromatin filaments become twisted and form a fine spireme — noyaux 
leptotenes — and later this thread is gathered into a tangle at one portion 
of the nucleus, leaving a clear space with faintly staining nuclear membrane 
— noyaux synaptenes. The chromatin filaments emerge from the skein or 
grumeau and form a thick spireme filling the nucleus — noyaux pachytenes 
— the thickening of the cord being due to an apparent union of two 
parallel filaments by means of their achromatic processes. The final stages 
are where the cord becomes double, forming loops and rings — noyaux 
diplotenes — and later broken up and scattered throughout the nucleus 
forming the resting stages of the cell — noyaux dictyes. The development 
of the oocytes takes place from within outwards in the ovary, the further 
advanced stages being near the medullary portion. The cytoplasm of the 
cells increases in quantity with the increase in size of the nucleus, ultimately 
forming the deutoplasm. The more developed nuclei have rings of follicle 
cells surrounding them, and in the cytoplasm is seen a body of Balbiani. 
Y. Winiwarter lays much stress upon the karyolytic changes which occur 
in the cells, but in his subsequent paper these degenerative changes are not 
given an important place. As nuclear changes increase, the process of 
mitosis becomes diminished, so that there are two stages in the growth of 
the ovary with regard to its cells — first the period of multiplication or 
mitosis, and second the period of growth or formation of oocytes of the first 
order. In the paper published by v. Winiwarter and Sainmont the 
protobroque cells are described, not as having granular nuclei, but as having 
some chromatin filaments in their protoplasm. An intermediate stage 
between them and the deutobroque cells is shown, where the nuclei 
contain filaments in the form of short rods and masses with a nucleolus — 
noyaux transitoires or poussieroides. The stage of the leptotene cells is 
described as being very transitory. The synaptic stage is further sub- 
divided into noyaux synaptenes abreges. Mitosis is occasionally seen in 
the deutobroque cells, but as an exception, and doubtfully also in the noyaux 
