Further Studies on the Ovogenesis of Sagitta. 249 
taken was stained and restained with several different combinations 
but not with very satisfactory results. With safranin and lichterün, 
the granules held the safranin, while the yolk granules took the 
green. This evidence is in favor of their chromatin nature, but is 
of course insufficient. 
It is my purpose to secure more of this material another year 
for further study 1) of these granules, 2) of the embryology of the 
ovary and its ducts, and 3) of some points in the spermatogenesis. 
Summary. 
1. The so-called sperm-oviduct of Sagitta is merely a sperm-duct. 
2. A temporary oviduct is formed for each laying, between the 
sperm-duct and the germinal epithelium. This duct appears to be 
opened up by the activity of the individual eggs pushing their way 
out of the ovary proper and in between the germinal epithelium 
and the sperm-duct. 
3. The chromosomes preserve their individuality from the time 
when reduction in number occurs in the very young oocytes to their 
appearance as tetrads in the first polar spindle. 
4. The scattered chromosomes of the germinal vesicle are collected 
by currents in the karyoplasm, at the point where the first polar 
spindle is formed. 
5. There is a preliminary longitudinal splitting of the chromo- 
somes during their reduction in size. 
6. The tetrad is bilaterally symmetrical, indicating that it is 
composed of two chromosomes paired longitudinally. 
7. The chromosomes in the young oocytes conjugate longi- 
tudinally, instead of end to end as in the spermatocytes. 
8. In Sagitta, we have two types of conjugation of the chromo- 
somes in oocyte and spermatocyte, and two corresponding types of 
maturation divisions, giving, however, equivalent results. 
9. The chromatin(?) granules which result from the reduction 
in size of the chromosomes pass directly out from the nucleus into 
the cytoplasm along strands of karyoplasm, 
Hopkins Laboratory, Pacific Grove, California, 
June 21, 1904. 
