542 
The Ohio Naturalist. 
[Vol. IX, No. 8, 
SUMMARY. 
1. The chromatin network of the resting nucleus is trans¬ 
formed into a continuous spirem with no definite evidence of the 
presence of protochromosomes. 
2. No spliting or doubling of the linin thread or of the 
rchromatin granules was observed; the chromosomes are appar¬ 
ently arranged end to end in the spirem. 
3. Synizesis appeared at various stages but was apparently 
not constant for any particular stage. 
4. The continuous spirem shortens and twists into 8 loops, 
•radiating outward toward the nuclear wall, the crossing threads 
forming a central knot. 
5. The 8 loops break apart at the center to form the 8 
bivalent chromosomes. 
*6. Fine connecting strands often appear between the 
chromosomes and the nuclear wall or between the chromosomes 
themselves. 
7. The chromosomes show a striking difference as to shape 
and size. 
8. The pair of univalent chromosomes, which must have 
united to form a bivalent chromosome are alike in shape and 
size and apparently represent maternal and paternal bodies. 
LITERATURE. 
Brown, W. H. The Nature of the Embryo-Sac of Peper- 
omia. Bot. Gaz. 46:445-460, 1908. 
Gates, R. R. A Study of Reduction in Oenothera rubri- 
nervis. Bot. Gaz. 46:1-34, 1908. 
Schaffner, J. H. The Division of the Macrospore Nucleus. 
Bot. Gaz. 23:430-452. 1897. 
—The Reduction Division in the Microsporocytes of 
Agave virginica. Bot. Gaz. 47:198—214. 1909. 
EXPLANATION OF PLATE XXXII. 
Fig. 1. Mother cell of microsporocytes. 
Fig. 2. The same. 
Fig. 3. Microsporocyte with chromatin network and showing irregular 
masses. 
Fig. 4. Microsporocyte with delicate linin threads and prominent 
chromatin granules. 
Fig. 5. Microsporocyte with expanding nucleus and more prominent 
threads. 
Fig. 5a. Single threads showing rows of chromatin granules. 
Fig. 6. Threads of network adjusting themselves into a definite spirem. 
Fig. 7. Spirem becoming thicker. 
Fig. 8. Synizesis stage; massing of chromatin. 
Fig. 9. Spirem showing irregular twisting. 
Fig. 9a. Single threads of same stage. 
Fig. 10. Spirem beginning to be thrown into definite loops, the threads 
crossing and massing in the center. 
