152 
Katharine Foot and E. C. Strobell 
can be countod with equal clearness. We have placed these Photos side 
by side in Order to facilitate a comparison of the two groups of chromo- 
somes. It would seem that such a comparison ought to throw some light 
on the method of pseudo-reduction, but it is evident this is not the case. 
The bivalent chromosomes of Photo 2 indicate merely that they have 
passed through some profoimd changes between the stages shown in 
Photos 1 & 2 — changes which have presumably occiured after the telo- 
phase of the last oögonial di\dsion. We have, however, been unable to 
find any satisfactory evidence of the occurrence of these intervening 
stages. The strongest evidence we have that the bouquet stage is pre- 
ceded by a rest stage, is the fact that a nucleolus — the structure typi- 
cally associated with the rest stage is frequently found in the bouquet 
nucleus. It is an interesting fact that this nucleolus sometimes appears 
elongated and closely resembles the chromosome nucleolus figured in the 
spermatogenesis of so many forms. 
Longitudinal sections of a whole ovary (text-fig.) show that the 
pseudo-reduced chromosomes shown in Photos 2 and 3 are found at the 
extreme proximal end of the ovary on or near the periphery and in such 
dose relation to the oögonial metaphases that the indications are they 
arise without the Intervention of a typical resting stage. 
StEVEXS (02) figures such a condition in the oögenesis and sperniato- 
genesis of Sagitta. She figures one type of a spermatogonial division in 
which synapsis (peudo-reduction) appears at the telophase (fig. 19B). She 
says : “these figimes lead me to think that the so called synapsis stage occurs 
in Sagitta at the dose of the final spermatogonial division, the chromosomes 
uniting in paks at the poles of the spindle” (p. 234). Of the bouquet stage 
in oögenesis she says: “the regulär arrangement of loops in such oöcytes 
as are shown in figures 5 and 6 indicate the possibility that they may have 
begun their development after the last oögonial division without an inter- 
veiiing resting stage and that the reduction in number to 9 chromosomes 
may have recently taken place” i). 
There are many cases on record in which pseudo-reduction (synapsis 
of some authors) occurs at the telophase of the last spermatogonial division 
without the intervention of a typical rest stage, but in the majority of 
cases typical stages leading up to the pseudo-reduced chromosomes have 
been demonstrated. For example, McClung (02) States “it has alreadw 
1) The behavior of the cluroraosomes of the two forms, Allolobophoraa,n6. Sagitta 
does not correspond so closely in the later stages, for Stevens finds the bivalent chromo- 
somes of the bouquet stage persisting through the entire grov^dh period. 
