On the ovogenesis and spermatogenesis of Sagitta bipunctata. 231 
granules are seen attached to the chromosomes. Fig. 12 shows a 
section of a nucleus containing one long slender chromosome with 
four granules, and fewer granules outside of the nuclear-membrane 
than in Fig. 11. In Fig. 15, such a chromosome and parts of two 
others with large granules are shown with higher magnification. 
Fig. 14 shows a case where all the chromosomes, slightly longer than 
those in Fig. 11, were grouped in the center of the nucleus in two 
sections, the nuclear plasm was deeply stained, and only a few granules 
were outside of the membrane. That these cast out granules are 
chromatin removed from the chromosomes during the process of their 
reduction in size seems evident ; but whether they pass out as granules 
through the partly dissolved membrane, or go into solution in the 
nuclear-plasm, pass out, and are reformed, it is impossible to tell with 
certainty. The fact that one rarely finds such granules in the nucleus 
except in connection with the chromosomes, would favor the latter 
supposition, while the appearance of the group of granules in a region 
of deeper-staining substance, separated from the nucleus by a scarcely 
perceptible membrane (Fick, 1899), gives one the impression that 
there has been a flow of nuclear-plasm and granules out into the 
cytoplasm. 
Figs. 13a—i give a series of chromosomes drawn with the same 
magnification as Fig. 2, to show the changes which occur during the 
reduction from the greatest length, a, in the stage shown in Fig. 10, 
to the shortest, i (about one eighth the length of a) as shown 
in Fig. 2b and Fig. 11. Throughout the series the body of the 
chromosome seems to contain irregular granules, closely packed 
together in the reduced forms, and spread apart in the longer and 
branched forms. The branching and reduction in size recall the 
figures of RÜCKERT (1892) for ovocytes of Pristiurus, but the branching 
is much less regular. RÜCKERT also describes a similar relation of 
granules or nucleoli to the chromosomes, but in Pristiurus the nucleoli 
remain within the nucleus. In Sagitta, there is no such doubling of 
the number of chromosomes as in Pristiurus, but the number nine is 
maintained without interruption from the beginning of the growth 
period, to the time of fertilization, the splitting of the chromosomes 
appearing in the first maturation division (Bovert, 1890). 
Thus in Sagitta, there is no disappearance and reappearance of 
chromatin in varying forms, as described by Carnoy & LEBRUN 
(1897, 1898, 1899) and by Frcx (1893, 1899) for Amphibia; but un- 
questionable continuity of the reduced number of chromosomes 
