144 
R. A. HARPER 
EXPLANATION OF THE PLATES XI AND XII 
Figures 7 and 16 were drawn with the aid of the camera lucida from preparations 
stained with the triple stain. Zeiss apochromatic objective 3 mm. N.Ap. 1.3, 
ocular 8. 
The microphotographs were made with the Zeiss apochromatic objective 16 
mm. Oc. 4 with Cramer's micro-ray filter No. 7 except in case of the iron haematoxylin 
preparations, figures 15, 17, and 18. 
Plate XI 
Fig. I. Part of radial section of young sporange before cleavage, showing two 
capillitial threads, the vacuolated condition of the middle zone of the spore-plasm 
and the distribution of the nuclei. 
Fig. 2. Entire horizontal radial section of sporange at stage when the spore- 
plasm has become quite homogeneous, showing radial capillitial threads and the 
distribution of the nuclei. Columella containing reticulated gelatinous material 
extruded in formation of the sporange. X 90. 
Fig. 3. Horizontal section, later stage, showing rows of extruded droplets of 
cell sap on the capillitial threads. Columella showing lobed concretion. X 90. 
Fig. 4. Like fig. 3. Well-developed concretion in columella. X 90. 
Fig. 5. The droplets of cell sap have become ellipsoidal preparatory to flowing 
together. X 90. 
Fig. 6. Horizontal section later stage with thin, watery sheaths around the 
capillitial threads, X 90. 
Fig. 7. Drawing showing arrangement of the nuclei along the plasma mem- 
brane of the watery sheath surrounding a capillitial thread. X 800. 
Fig. 8. Horizontal section showing a little later stage than fig. 6. X 90. 
Fig. 9. Horizontal section showing the watery sheaths around the capillitial 
threads more strongly developed. Cleavage beginning at (a). The checking of 
the protoplasm is artefact. 
Plate XH 
Fig. 10. Tangential section showing cleavage furrows forming about the 
capillitial openings. X 90. 
Fig. II. Stage a little later than shown in fig. 9. Cleavage at {a) and (b). 
X 80. 
Fig. 12. Vertical section showing early stage in cleavage. X 90. 
Fig. 13. Tangential section showing cleavage. X 90. 
Fig. 14. Tangential section showing a little later stage than fig. 13. X 90. 
Fig. 15. Advanced stage in cleavage. X 90. 
Fig. 16. Drawing of segmenting block of spore-plasm showing cleavage fur- 
rows and resting nuclei, others in equatorial plate stage. X 650. 
Fig. 17. Late stage of cleavage. X 65. 
Fig. 18. Vertical section of entire sporange showing spores, stipe and hypo- 
thallus. Stipe and hypothallus filled with granular concretionary material. 
