100 BOTANICAL GAZETTE [ AUGUST 
EXPLANATION OF PLATES IV-VI. 
The plates are reduced two-thirds. The magnifications given refer to the 
original magnifications of the drawings before reduction. The combinations 
used were for the most part a -;/y Leitz immersion objective, and nos. 2, 4, and 
12 Reichert oculars. 
Plate IV. 
Fic. 1. Longitudinal section of stem, showing the origin of the young. 
stamen branches. X 135. 
Fic. 2. Longitudinal section of young stamen branch. X 780. 
Fic. 3. The same a little older. X 78o. 
Fic. 4. Cross section of young stamen at the same age as fig. 3. X 780. 
Fic. 5. Longitudinal section of young stamen, showing sporogenous Cells. 
x 1200. 
Fic. 6. Young stamens with pollen mother cells in the sporangia. X 135- 
Fic. 7. Longitudinal section of stamen, showing pollen mother cells, 
tapetum, endothecium, epidermis, and one layer of cells between the tape- 
tum and the endothecium. X I200. 
Fic. 8. Cross section of microsporangium, showing the pollen mother cells 
and tapetum. X 1200. 
FiG. 9. Cross section of microsporangium, showing the pollen mother 
cells somewhat separated. xX I200. 
F1G. to. Cross section of microsporangium, showing the disintegration of 
the immediate cells. X 1200 
Fic. 11. Section of a young leaf showing multinuclear stellate cells. 
x 650. 
Fic. 12. Cross section of microsporangium, showing disorganization of 
the tapetal cells. X 1200. 
FiG. 13. Cross section of an anther just before dehiscence. X 650. 
Fic. 14. Longitudinal section of the wall of the microsporangium. X 1200. 
Fig. 15. A young branched stamen, showing the position of the hairs. 
Fic. 16. Cross section of one of the interstaminate hairs. 1200. 
Fic. 17. The same. F200: 
Plate V. 
Fic. 18. First division of the pollen mother cell. x 1200. 
FiG. 19. Second division of the pollen mother cell. < 1200. 
Fic. 20. Tetrad. X 1200. 
