1905] MOORE—SPORGGENESIS :-IN PALLAVICINIA 95 
11. Juet, H. O., Die Kerntheilung in den Pollenmutterzellen von Hemero- 
callis julva und die bei denselben auftretenden Unregelmissigkeiten. Jahrb. 
s. Bot. 30:205-226. pls. 6-8. 1897. 
aes E., Zur Frage nach dem Ursprung der verschiedenen Zellen- 
elemente der Insectenovarien. Zool. Anz. 8:581-586, 599-605. 1885. 
Lawson, A. A., Origin of the cones of the multipolar spindle in Gladiolus. 
Bor. Gaserte 30:145-153. pl. 12. Ig00. 
14. Merriman, M. L., Vegetative cell-division in Allium. Bort. GAZETTE 
37:178-207. pls. -11-F3. 1904; 
Moors, A. C., The mitoses in the spore mother cell of Pallavicinia. Bor. 
GAZETTE 36: 384-388. figs. 6. 1903. 
Mortierr, D. M., Beitrage zur Kenntniss der Kerntheilung in den Pollen- 
mutterzellen einiger Dikotylen und Monokotylen. Jahrb. Wiss. Bot. 
La 
N 
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rs 
84 
al 
an 
7: 
. V., Ueber Entstehung der ee Spindel 
bei baukcims Tahu: Wiss. Bot. 30:5-14. pls. 1-2. 1 
Wacer, H., The nucleolus and nuclear division in ee root apex of Phase- 
olus. es Botany 18:29-55. pl. 5. 1904. 
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EXPLANATION OF PLATES III AND IV 
All figures except jig. 28 were made with a Zeiss 2™™ apochromatic objective 
and a no. 12 ocular. Fig. 28 was made with the same objective, but with no. 8 
ocular. A Bausch and Lomb camera lucida was used for all drawings. In jig. 2 - 
all the plastids of the cell are shown; in other cases only those immediately sur- 
rounding the nucleus. 
Fic. 1. Enlarged nucleus of spore mother cell in early stage of preparation 
for division; the nucleolus is conspicuous and the appearance and arrangement 
of the chromatin indicate the condition of synapsis. 
Fic. 2. Spirem condition, showing linin thread loosely wound with deeply 
staining chromatic droplets at intervals. 
Fic. 3. Thicker and shorter spirem; chromatic droplets fewer and larger; 
lobes of nucleus distinctly rounded. 
Fic. 4. Spirem further shortened; chromatic droplets crowded together; 
the thread appears double. 
Fic. 5. Ends of spirem thread, showing that it is double. : 
Fic. 6. Aggregation of chromatic droplets just previous to segmentation of 
chromosomes; probably time of tetrad formation; the nucleolus seems to be 
fragmenting. 
Fic. 7. Later stage than fig. 6. 
Fic. 8. Equatorial plate stage, showing group of eight tetrads. 
Fic. 9. Equatorial plate stage, later than fig. 8; tetrads not so clearly defined; 
nucleclus feagmienti ing. 
